PHILIPS PM3357 (01) PDF Document

The PHILIPS PM3357 Digital Storage Oscilloscope (DSO) range includes models with the following easy-to-use features:

• 60 MHz analog oscilloscope for PM3350A and PM3355

• 100 MHz analog oscilloscope for PM3365A and PM3375

• 100 MSamples/s single shot digital acquisition on both channels for PM3350A and PM3365A

• 250 MSamples/s single shot digital acquisition on both channels for PM3355 and PM3375

• Auto Set for instant signal viewing in both analog and digital oscilloscope modes

• Cursors for time and amplitude measurements in digital oscilloscope mode

• Reference memories and non-volatile storage of all waveforms

• Optional interface facilities for remote control and hard copy output

• Storage of 64 front settings

For the correct and safe use of the PHILIPS PM3357, it is essential to understand the following statements:

CAUTION: Is used to indicate correct operating or maintenance procedures in order to prevent damage to or destruction of the equipment or other property.

WARNING: Calls attention to a potential danger that requires correct procedures or practices in order to prevent personal injury.

Follow these steps for initial setup of your PHILIPS PM3357:

1. Connect the oscilloscope to the mains (line) voltage.

2. Switch the oscilloscope on by means of the push-button POWER LINE ON.

3. Adjust the TRACE ROTATION by means of a screwdriver so that the trace is parallel with the horizontal graticule lines.

4. Connect a probe to input A of the oscilloscope.

5. Connect the other end of the probe to the CAL output of the oscilloscope.

6. Press the AUTO SET key.

The AUTO SET function will automatically set all relevant parameters of the oscilloscope (attenuator setting, time base setting, and trigger source setting) for an optimum trace. If you are using a 10:1 or 100:1 attenuator probe, it may be necessary to adjust it for correct compensation according to the instructions in the probe manual.

Earthing (Grounding): Before making any connections to the inputs, the PHILIPS PM3357 must be connected to protective earth (ground) via the three-core mains (line) cable. The mains plug must be inserted into a socket outlet with a protective earth contact. Any interruption of the protective conductor, inside or outside the instrument, is likely to make the instrument dangerous.

Mains (Line) Voltage Cord and Fuses: The oscilloscope has a tapless switched-mode power supply that covers most nominal voltage ranges from 100 V to 240 V (r.m.s.) at a frequency range of 50 Hz to 400 Hz. The instrument must be disconnected from all voltage sources when renewing a fuse. The mains (line) fuse rating is 1.6 AT delayed-action, 250 V.

To replace the fuse:

1. Disconnect the instrument from the mains (line).

2. Remove the cover of the fuseholder by means of a screwdriver.

3. Fit a new fuse of the correct rating and refit the cover of the fuseholder.

The PHILIPS PM3357 is provided with a built-in memory back-up circuit, which requires batteries to be fitted. Note that batteries are not factory installed. The memory function works when the oscilloscope is switched off from the front panel or when the mains supply is interrupted for more than 20 ms.

To replace the two LR6 Alkaline Penlight batteries:

1. The instrument must be disconnected from the mains (line).

2. Remove the screw that holds the top cover at the rear of the instrument.

3. Gently push the cover backwards until it can be lifted.

4. Remove the cover by lifting it clear of the instrument. The memory battery back-up unit is now accessible on the instrument’s rear panel.

5. Ease off the clip that holds the memory back up unit to the chassis.

6. Gently slide the battery holder out of the chassis.

7. Install both batteries in their holders. The installation direction is shown on the battery holder.

Note: When replacing the memory back-up unit, take care not to damage the wiring in the vicinity of the battery holder.

By pulling both handle ends outwards away from the instrument, the handle on the PHILIPS PM3357 can be rotated to allow for the following instrument positions:

• vertically on its rear feet;

• horizontally on its bottom feet;

• in two sloping positions on the handle.

Attention: Do not position the oscilloscope on any surface which radiates heat, or in direct sunlight. Ensure that the ventilation holes at the rear and top are free from obstruction.

Front Panel Connectors:

• CAL: Amplitude calibrated output socket.

• Ground Symbol: Measuring earth (ground) socket (banana).

• A: BNC input socket for channel A with probe indication.

• EXT: BNC input socket for channel EXTERNAL.

• B: BNC input socket for channel B with probe indication.

Rear Panel Connectors:

• Z-MOD: BNC input socket for Z-modulation of the CRT trace.

• ANALOG PLOT OUT: Plot output socket to connect the oscilloscope to an analog XY plotter.

• LINE IN: Mains (line) input socket including fuse holder.

Optional Rear Panel Connectors:

• IEEE BUS OPTION: Input/output socket to connect the oscilloscope to a IEEE 488/IEC 625 interface.

• RS232 BUS OPTION: Input/output socket to connect the oscilloscope to an RS-232C/V24 interface.

After switching on the PHILIPS PM3357 with the POWER LINE ON push button, you can adjust the screen controls for optimum illumination, trace, and spot quality.

• The trace and text intensity is set by the INTENS rotary knob.

• A sharp display is obtained by the FOCUS rotary knob.

• The screw driver control TRACE ROTATION is used to set a grounded trace parallel with the horizontal graticule lines.

• The graticule of the screen can be lit-up by the ILLUMINATION rotary knob, which can be useful in dark environments or for making photographs.

The viewing area of the PHILIPS PM3357 consists of the screen of the Cathode Ray Tube (CRT) and a Liquid Crystal Display (LCD).

The CRT screen is divided in a 10 x 8 divisions area. Each division contains five sub-divisions. On the left side of the CRT screen, four lines are marked with the values 100%, 90%, 10%, and 0%. These marked lines can be used for percentage measurements or rise time measurements.

The LCD indicates all the selected active functions, settings, and parameters. Its layout is logically divided into areas according to the keys and knobs. A flashing segment indicates a situation that requires your special attention, for example:

• an incorrect selection of knobs/keys controls.

• a VAR rotary knob is in an uncal position.

• the end of an UP-DOWN control range.

• a key has been operated during the PLOT action.

• the DISPL PART UP-DOWN key has been pressed in TB MAGN x1 mode.

• display of register only.

The UP-DOWN keys on the PHILIPS PM3357 select the required setting out of a range of settings possible for that function. They are used for the attenuator setting, the time base setting, the trigger delay setting, and the display part setting.

VERTICAL ATTENUATOR SETTING CHANNEL A & B (Keys: A, B)

Selection of vertical attenuation.

• Analog: 2 mV/div … 10 V/div in 1-2-5 sequence

• Digital: 2 mV/div … 10 V/div in 1-2-5 sequence

HORIZONTAL TIME-BASE SETTING (Key: TB)

Selection of time-base speed.

• Analog: 0.5 s/div … 50 ns/div in 1-2-5 sequence

• Digital:

– PM3350A: 50 s/div … 0.5 µs/div in 1-2-5 sequence

– PM3355: 50 s/div … 0.2 µs/div in 1-2-5 sequence

– PM3365A: 50 s/div … 20 ns/div in 1-2-5 sequence

– PM3375: 50 s/div … 20 ns/div in 1-2-5 sequence

TRIGGER DELAY SETTING (Key: TRIG DEL)

Selection of trigger delay.

• Analog: not available

• Digital:

– PM3350A: -10 div … + 2500 div in 1 div sequence (in TB = 50 s/div … 0.5 µs/div)

– PM3355: -10 div … + 5000 div in 1 div sequence (in TB = 50 s/div … 0.2 µs/div)

– PM3365A: -10 div … + 2500 div in 1 div sequence (in TB = 50 s/div … 0.5 µs/div), 0 div … + 20 div in 1 div sequence (in TB = 0.2 µs/div … 20 ns/div)

– PM3375: -10 div … + 5000 div in 1 div sequence (in TB = 50 s/div … 0.2 µs/div), 0 div … + 20 div in 1 div sequence (in TB = 0.1 µs/div … 20 ns/div)

DISPLAY PART SETTING (Key: DISPL PART)

Selection of the displayed part of a magnified trace.

• Analog: not available

• Digital: 1/16 … 16/16 sequence depending on TB MAGNIFY value.

The rotary knobs on the PHILIPS PM3357 provide continuously-variable adjustment of their function.

• Y POS (Channel A): Adjusts the vertical screen position for channel A.

• VAR A: Adjusts the variable attenuation for channel A. It is in the CALibrated position when fully clockwise.

• Y POS (Channel B): Adjusts the vertical screen position for channel B.

• VAR B: Adjusts the variable attenuation for channel B. It is in the CALibrated position when fully clockwise.

• X POS: Adjusts the horizontal screen position for the time-base.

• VAR (Time-base): Adjusts the variable time-base (not in DIGITAL MEMORY). It is in the CALibrated position when fully clockwise.

• TRIG LEVEL: Adjusts the trigger level.

• HOLD OFF: Adjusts the hold off time. It is in the normal position when fully clockwise (minimum HOLD OFF).

In digital memory mode, the five softkeys located below the CRT on the PHILIPS PM3357 are used for various functions like AMPLITUDE CALCULATIONS, TIME CALCULATIONS, PROCESS MEASUREMENTS, choice of REGISTER MEMORY, and the ZOOM facility. All calculation and manipulation facilities are activated via successive steps through the softkey menu structure.

When a menu is activated, the CRT screen shows two text areas. The top text area displays calculation information and channel settings. The bottom text area shows all functions assigned to the five softkeys.

The main menu options are:

• CURSORS: Enters the cursor control menu for manual measurements.

• AVERAGE: Activates signal averaging to reduce noise.

• PROCESS: Enters menus for AVERAGE and ENVELOPE functions.

• MEMORY: Enters menus for storing and recalling waveforms and settings.

• SETTINGS: Toggles the display of instrument settings on or off.

• TEXT.OFF: Removes all text from the screen.

Navigating through the menus is done by pressing the corresponding softkey. The ‘RETURN’ softkey will take you back to the previous menu level.

When using the PHILIPS PM3357 in analog mode, you can make the following vertical adjustments:

• Vertical display mode selection: Press the A/B key to select the channel you want to see: A, B, or A and B simultaneously. If ADD is in use, you can switch off channels A and B.

• Adjustment of the absolute zero level: Press the GND key to interrupt the input signal and ground the input path. With the Y POS rotary knob, the zero level can be positioned anywhere on the screen. This is necessary for all DC measurements.

• Channel coupling: Press the AC/DC key to select the coupling. In AC position, the DC component of the signal is rejected. In DC position, the full bandwidth is available. AC coupling is used when a small AC signal must be measured on a large DC voltage.

• Vertical amplitude adjustment: Operate the V…mV UP-DOWN key for the desired channel to choose a setting from 2 mV to 10 V per division in a fixed 1-2-5 sequence.

• Vertical variable attenuation: Adjust the VAR rotary knob. When not fully clockwise, the UNCAL indication “>” flashes in the LCD. This allows you to set a measured signal to 100% for percentage-based measurements, like rise-time.

• Selection of ALTERNATED or CHOPPED display: When two signals are displayed, press the ALT/CHOP key. In alternate mode, the CRT traces one signal sweep and then the other. This is used for high-speed time-base settings. In chop mode, the beam chops from one signal to the other at a fast frequency, suitable for low-speed signals.

• Selection of ADD, NORMAL or INVERTED display: Press the ADD/INVERT key. “INVERT” is active on channel B. In ADD mode, channel B is added to channel A (A + B). In the ADD INVERT mode, channel B is subtracted from channel A (A – B). The differential mode (A – B) is useful for rejecting common-mode signals, like hum.

In analog mode, the following horizontal selections can be made on the PHILIPS PM3357:

• Selection of X deflection or horizontal time-base: Press the X DEFL key. In the X deflection mode, the oscilloscope shows one signal as a function of another (X-Y graph). The required X-axis signal is selected by the TRIG OR X SOURCE key (A, B, EXT, or LINE). In horizontal time-base mode, the display shows the measured signal versus time (Y-t graph).

• Selection of horizontal time scale: Use the TB s…µs UP-DOWN key to select the time-base speed in a 1-2-5 sequence. Use the rotary knob VAR to make fine adjustments between the 1-2-5 steps. The X MAGN key can be used to expand the time-base 10 times.

• Horizontal Position: Operate the X POS rotary knob to shift the trace across the screen in the horizontal direction.

In analog mode, you can configure the trigger on the PHILIPS PM3357 as follows:

• Time-base trigger mode: Use the TB TRIG MODE key.

– AUTO: The horizontal sweep normally starts when a trigger occurs. If no trigger is detected within 100 ms after the last sweep, a sweep start is automatically generated. A trace is always visible.

– TRIG: The horizontal sweep will only start on a trigger pulse derived from the selected trigger source.

– SINGLE: The horizontal sweep runs only once after it is armed by the RESET key and receives a trigger pulse. Useful for capturing single events.

• Trigger source selection: Press the TRIG OR X SOURCE key to select from: A (channel A), B (channel B), A B (composite from A and B), EXT (external), or LINE (mains voltage).

• Trigger level: Adjust the TRIG LEVEL rotary knob to set the voltage level on the signal waveform where the trigger occurs.

• Trigger coupling: Use the TRIG COUPL key to select from six modes:

– P-P: Peak-to-peak triggering with automatic range of the TRIG LEVEL knob.

– DC: Full bandwidth of the trigger channel is available.

– TVF: TV frame triggering for slow TV frame (field) synchronization pulses.

– TVL: TV line triggering for fast TV line synchronization pulses.

– LF: Low-frequency reject; signal is passed through a high-pass filter with a cut-off of 50 kHz.

– HF: High-frequency reject; signal is passed through a low-pass filter with a cut-off of 50 kHz.

• Trigger slope selection: Press the slope key to select triggering on a positive-going slope or a negative-going slope.

• Hold-off time: Use the HOLD OFF rotary knob to prevent “false” triggering on complex signals like pulse trains. It inhibits the trigger for a period of time after a sweep is completed, ensuring synchronization on the first pulse of a series.

When using the PHILIPS PM3357 as a digital storage oscilloscope (by pressing the DIGITAL MEMORY key), the following additional functions are available:

• Dotted or joined display: Press the DOTS key to switch between a display built-up by “dots” of samples or an interpolated “dotjoined” display where dots are interconnected by a line.

• Memory Operations: The oscilloscope has a display memory for normal operation and three register memories (R1, R2, R3) for storing reference waveforms.

– Loading of register memory: Press the LOAD key to store the signal from the display memory into a selected register. Waveforms in registers are stored even after power down if batteries are installed.

– Display of register memory: Press the DISPLay key to show the contents of the display memory and the selected register memory together on the screen for comparison.

– Status of register memory: Press the STATUS key once to show the full settings of the selected register memory. Press it twice within one second to show the complete settings of the display memory (R0).

• Trigger Delay: The TRIG DEL UP-DOWN key allows for PRE- and POST triggering. You can look before the trigger point (pre-triggering, e.g., delay = -10 divisions) or far after the trigger point (post-triggering, e.g., delay = +2500 divisions).

In digital storage mode, the horizontal time-base on the PHILIPS PM3357 has three modes:

• ROLL (50 s/div … 1 s/div): Used for lower frequency signals. The screen build-up is from right to left.

• RECURRENT (0.5 s/div … see model): The screen build-up is from left to right. This is the standard mode for most signals.

• SAMPLING (see model): Used for high-frequency repetitive signals. The screen build-up is from left to right. Note that the PM3350A/55 models do not have a sampling mode.

Horizontal Magnification:

By pressing the X MAGN key, a horizontal magnification of 2, 4, 8, 16, or 32 times can be obtained. Any part of interest in a magnified signal may be selected for display by the DISPL PART UP-DOWN key. The LCD bar shows the actual position of the displayed part in relation to the memory length. You can return to x1 magnification by pressing the X MAGN key and then the RESET key simultaneously.

To use cursors, you must be in digital mode. First, press the softkey below CURSORS in the main menu. This activates two cross-shaped MAIN CURSORS on the waveform. The trace on which the cursors operate can be selected in the SELECT menu.

• Use the CONTROL menu to position the two MAIN CURSORS horizontally to the left and to the right. Cursor 1 and Cursor 2 can not pass each other to avoid erroneous negative time.

• Depending on previous measurement selections, either a horizontal dotted line or two so-called LOCATE cursors may also be visible. The dotted line serves as a ground reference point. The small LOCATE cursors are placed on the waveform in between the MAIN cursors to indicate exactly where an automatic measurement is being calculated.

• All cursor measurement results are shown on the top text line of the screen.

To perform a specific measurement, enter the CALCULATE menu and choose either AMPL (Amplitude) or TIME.

To perform automatic measurements, enter the CURSORS menu, then the CALCULATE menu from the softkeys. All measurements are calculated on the signal portion between the two main cursors.

Amplitude Measurements (AMPL menu):

• Vpp: Calculates the peak-to-peak value of the signal. The LOCATE CURSORS indicate the signal top and bottom where the calculation is related.

• RMS: Calculates the Root Mean Square value of the waveform relative to the dotted ground line. To set the ground reference, press the GND key and adjust the trace to the desired vertical position, then release the GND key.

• MEAN: Calculates the mean value of the waveform relative to the dotted ground line.

• ABS: Calculates the vertical voltage differences between the dotted ground line and MAIN Cursor 1 (C1 value) and MAIN Cursor 2 (C2 value).

Time Measurements (TIME menu):

• FREQ: Calculates the signal frequency, provided at least one signal period is present between the MAIN cursors. The LOCATE cursors indicate the signal period used for calculation.

• PERIOD: Calculates the duration of one signal period (T) between the MAIN cursors.

• WIDTH: Calculates the width of the first pulse (tw) seen from the left cursor. The LOCATE cursors indicate the part of the pulse used for calculation.

• RISE: Calculates the rise- or fall-time (tr) of the first signal slope seen from the left cursor. The 100% level is taken to be the vertical value between the MAIN cursors. The LOCATE cursors indicate the part of the slope (between 10% and 90%) used for calculation.

ZOOM function:

The ZOOM function magnifies a part of the signal while retaining full sample resolution over the selected part. This is useful when part of the signal needs to be examined in more detail.

1. In digital mode, use the main cursors to select the part of interest on the wanted trace.

2. Enter the ZOOM menu and activate the RESTART function. A new acquisition will be made in the adapted time base setting and delay time.

3. The selected part is resampled using the full memory at a higher sample rate, resulting in higher resolution.

• The REVERSE function resamples at the previous settings.

• The CENTER function sets the MAIN cursors horizontally to +2 DIV and -2 DIV from the screen center.

AUTO ZOOM function:

This mode simulates a delay time-base function by displaying a main time-base signal and a delayed time-base signal together.

1. Store the main time-base signal in one of the register memories (R1, R2, or R3).

2. Load the signal to be examined into the selected register memory and display this on the screen.

3. When AUTO ZOOM is activated, the MAIN CURSORS are set on the stored signal, and the LOCATE CURSORS are on the live signal. These cursors indicate the part of the signal that is displayed in more detail.

4. The live signal can be shifted across the screen, or the time-base can be expanded or separated up or down via the softkeys.

The PROCESS menu on the PHILIPS PM3357 allows you to define one of two processes, AVERAGE or ENVELOPE. The two processes can never be active at the same time.

PROCESS AVERAGE menu:

This function suppresses noise without losing bandwidth. Every dot is calculated after every sweep based on a formula that combines the new sample with the previous average. The averaging factor “C” can be selected: 2, 4, 8, 16, 32, 64, 128, or 256. The bigger C is, the slower the dot positions change. AVERAGE is a continuous process until switched off. It is started again when the INIT softkey is pressed or when triggering/amplitude control is changed.

PROCESS ENVELOPE menu:

This function stores the minimum and the maximum of each sample position over the sweeps taken. The ENVELOPE is stored in the selected reference register (R1, R2, or R3) and default displayed together with the acquired signal (display memory R0). This is useful for detecting signal jitter or variations over time. The process is continuous until switched off and is restarted by pressing the INIT softkey or when triggering/amplitude control is changed.

The MEMORY menu on the PHILIPS PM3357 is an intermediate menu used to choose between the FRONTS menu, REGISTERS menu, and SHIFT menu.

• FRONTS menu: With this menu, it is possible to store up to 63 different front panel key settings. These settings are still stored in the oscilloscope memory after power down for recall at the next power up (if backup batteries are fitted). Select a memory location and press the SAVE softkey. To activate a stored setting, select it and press the RECALL softkey.

• REGISTERS menu: In this menu, one of the register memories R1, R2, or R3 can be selected as the REFERENCE REGISTER MEMORY upon which operations can be performed.

• SHIFT menu: In this menu, a displayed trace can be positioned UPwards or DOWNwards on the screen. If CAL is pressed, the trace returns to its original position. This menu is only active if more than one trace is visible on the screen. Correct positioning is only possible in LOCK mode, as this is a post acquisition facility.

For waveform comparison, first select one of the register memories with the REGISTERS menu. Then, load a reference signal into the selected register memory by pressing the LOAD key. A measured “live” signal (R0) can then be compared with one of the stored reference signals by displaying the signals on screen simultaneously.

This mode is possible for all versions of the PHILIPS PM3357 oscilloscope. You can plot out the waveform(s), channel identification, and measuring graticule.

1. Enter the service menu by pressing the MENU key and keeping it pressed. Now also press the AUTO SET key, and * becomes visible in the LCD.

2. Press softkey APPL to enter the application preselect menu.

3. Press softkey PLOT.

4. If present, press softkey PLOT-KEY until “plot analog” appears in the top text area of the CRT.

5. Press softkey PLOT-A; this gives access to the set up menu for the analog plot mode.

6. From this menu, you can adapt the PLOTSPEED (range 20…2000 ms/dot) for slow-rate limitations and the PENLIFT (pen on paper at high or low level).

7. You can also choose whether to plot with GRID on or off.

8. Press the front panel key AUTO SET in order to leave the service menu.

The plot output information is available at the 9 pin D-connector on the rear of the oscilloscope. The output signal consists of X and Y deflection signals of 1V (100 mV/div) and the penlift signal at TTL level.

These modes are only possible for the /40 (IEEE-488) or /50 (RS-232C) versions of the oscilloscope.

For IEEE-488 Interface (/40 version):

1. Enter the service menu by pressing MENU and then AUTO SET.

2. Press softkey APPL to enter the application preselect menu.

3. Press softkey IEEE to enter the IEEE set up menu.

4. Select the IEEE address with the ADDRESS softkey (0…30).

5. Select the IEEE mode with the T/L softkey (TALKER/LISTENER, TALK ONLY or LISTEN ONLY).

6. Press softkey RETURN, then press softkey PLOT.

7. To set up for a digital plotter, select “plot-digital” with the PLOT-KEY, then press PLOT-D. Select the plotter type and format (0.5x to 2x screen size).

8. To set up for a dot matrix printer, select “printer” with the PLOT-KEY, then press PRINTER. Select the printer type.

For RS-232C Interface (/50 version):

1. Enter the service menu by pressing MENU and then AUTO SET.

2. Press softkey APPL to enter the application preselect menu.

3. Press softkey RS232 to enter the RS-232C set up menu.

4. Press softkey BAUDRATE and adjust the OUT-SPD (output speed).

5. Press softkey DATA and adjust PARITY, STOP BIT, and DATA BIT.

6. Press softkey RETURN twice, then press softkey PLOT.

7. To set up for a digital plotter or dot matrix printer, select “plot-digital” with the PLOT-KEY, then press PLOT-D. Select the plotter type and format.

After setup, exit the service menu by pressing AUTO SET. The plot action is started by pressing the front panel PLOT key.

The APPLICATION PRESELECT MENU contains a number of operating functions that do not need to be entered frequently. To access it:

1. Press MENU and keep it pressed. Now also press AUTO SET.

2. The Service menu has now been entered, the LCD should indicate “***”.

3. Press APPL, which is one of the CRT softkeys.

4. The CRT should indicate “APPLICATION PRESELECT MENU” on the upper side of the screen.

From this menu, you can make selections using the softkeys for the following functions:

• PLOT: Enters menus to adjust plotter and printer parameters. You can select analog plot mode (PLOT_A), digital plot mode (PLOT_D), or printer mode (PRINTER) and define parameters like plot speed, penlift level, plotter type, format, and auto-plot settings.

• SNGL_SHOT: In analog single shot mode, you can define the single shot sequence: FIRST (always on channel A) or MULTI (alternated between channel A, B, and ADD).

• AUTO: For TV triggering after AUTOSET. Allows selection of TVF triggering mode after an AUTOSET command.

• IEEE (Optional): Define the IEEE mode and IEEE address.

• RS232 (Optional): Define RS-232C parameters such as OUTPUT SPEED, INPUT SPEED, PARITY, STOP BIT, and DATA BIT.