IEEE-488/IEC-625 BUS Interface and RS232-C/V24 BUS Interface for Digital Storage Oscilloscope PM3320A and 2 GHz Digitizing Oscilloscope PM3340 PM8956A/01
NOTE: The design of this interface is subject to continuous development and improvement. Consequently, this interface may incorporate minor changes in detail from the information contained in this manual.
© N.V. PHILIPS GLOEILAMPENFABRIEKEN-EINDHOVEN-THE NETHERLANDS-1989 Printed in the Netherlands.
1. | INTRODUCTI | ION | 1-1 |
---|---|---|---|
1.1 | How to use this manual | 1-1 | |
2. | INSTALLATI | ION INSTRUCTIONS | 2-1 |
2.1 | Initial inspection | 2-1 | |
2.2 | Removing the instrument covers | 2-3 | |
2.3 | Installing the P.C.B.'s and the cables | 2-4 | |
2.4 | Installing the instrument covers | 2-5 | |
2.5 | Settings of the interface | 2-5 | |
3. |
OPERATING
AND USER T |
INSTRUCTIONS INCLUDING REAL TIME CLOCK, DIGITAL PLOT
EXT |
3-1 |
3.1
3.1.1 3.1.2 3.1.3 |
Switching-on and power up routine
Switching on Power-on routine Default settings after switching-on |
3-1
3-1 3-1 3-1 |
|
3.2 | Additional features | 3-2 | |
3.3 | Explanation of optional control and option menu structure | 3-2 | |
3.4
3.4.1 3.4.2 3.4.3 |
Digital plot and print modes
Digital plot specification Digital print specification Digital plot and print menus |
3-20
3-20 3-24 3-26 |
|
4. | IEEE-488/1 | IEC-625 INTERFACE | 4-1 |
4.1 | Introduction | 4-1 | |
4.2 | Structure of the IEEE-488/IEEE-625 bus | 4-2 | |
4.3 | Bus-line functions | 4-4 | |
4.4 | The handshake procedure | 4-5 | |
4.5 | Addressing | 4-6 | |
4.6 | Address setting | 4-7 | |
4.7 | SRQ-service request and serial polling | 4-11 |
4.8 | The device status word | 4-13 |
---|---|---|
4.9 |
The device status register and the device status
enable register |
4-15 |
4.10 | Data transfer rate and timing specifications | 4-17 |
4.11 | Interface function repertoire | 4-24 |
4.12 | Electrical specifications | 4-24 |
4.13 | Mechanical specifications | 4-24 |
4.14 | Specification IEEE-488/IEC-625 interface | 4-26 |
4.15 | ISO-code table | 4-27 |
4.16
4.16.1 4.16.2 4.16.3 4.16.4 |
Multi line messages
GO TO LOCAL command GROUP EXECUTE TRIGGER command SELECTIVE DEVICE CLEAR command DEVICE CLEAR command |
4-28
4-28 4-28 4-28 4-29 |
RS232-C/V2 | 24 INTERFACE | 5-1 |
5.1 | Introduction | 5-1 |
5.2 | Definition of the RS232-C interface | 5-1 |
5.3
5.3.1 5.3.2 5.3.3 5.3.4 |
Data transmission
Synchronization Character length Baudrate Interface transmission modes |
5-1
5-2 5-2 5-2 5-2 5-2 |
5.4 | Initial setting | 5-3 |
5.5
5.5.1 5.5.2 |
Special interface functions
Service request and serial polling Remote local protocol |
5-7
5-7 5-8 |
Device clear ....................................
Data transfer rate calculation ....................................
RS232-C connector ..... 5-13
II
5.
5.5.3
5.5.4 5.6
5.8 5.9
6. | PROGRAMM | ING AN OSCILLOSCOPE | 6-1 |
---|---|---|---|
6.1 | Description of possible actions | 6-1 | |
6.2
6.2.1 6.2.2 6.2.3 |
Message protocol for oscilloscopes
Introduction Separators Message units |
6-2
6-2 6-3 6-4 |
|
6.3 | Oscilloscope programming | 6-6 | |
7. | PROGRAMM | ING CODES | 7-1 |
7.1
7.1.1 7.1.2 7.1.3 7.1.4 7.1.5 7.1.6 7.1.7 |
System codes
Separator Block separator Unit separator Call for identity Wait time delay Bus learn Number representation |
7-2
7-2 7-3 7-4 7-5 7-5 7-6 7-7 |
|
7.2
7.2.1 |
Super function codes
Super function codes available for this oscilloscope |
7-8
7-8 |
|
7.3
7.3.1 7.3.2 7.3.3 7.3.4 7.3.5 7.3.6 7.4 |
Main function codes and low function codes
Main functions available for this oscilloscope ALL main functions Main function VERTICAL Main function HORIZONTAL Main function MISCELLANEOUS Main function SPECIAL Error codes |
7-8
7-9 7-10 7-18 7-30 7-50 7-70 |
|
8. | PROGRAMMI | ING EXAMPLES | 8-1 |
8.1 | Introduction | 8-1 | |
8.2
8.2.1 8.2.2 8.2.3 8.2.4 |
Driver programs
Driver program HP85 (IEEE) Driver program IBM (IEEE) Driver program IBM (serial) Driver program P2000C (IEEE) |
8-1
8-1 8-2 8-3 8-4 |
8.3 | How to use the driver programs? | 8-5 | |
---|---|---|---|
8.4
8.4.1 8.4.2 8.4.3 8.4.4 8.4.5 8.4.6 8.4.7 8.4.8 8.4.9 |
Programming exercises
Text Data transfer Dumping data to a printer (serial printer) Use of UP/DOWN/NORMAL + SRQ Front settings Register savings Event counting Plotting register Ø, using a controller Bus learn |
8-7
8-7 8-10 8-10 8-11 8-12 8-13 8-14 8-15 8-14 |
|
9. |
CHARACTER
REAL TIME |
ISTICS OF IEEE-488/IEC-625, RS232-C/V24 INTERFACES AND CLOCK | 9-1 |
9.1 | IEEE-488/IEC-625 interface | 9-1 | |
9.2 | RS232-C interface | 9-2 | |
9.3 | Real time clock | 9-3 | |
9.4 | Front panel control | 9-3 | |
9.5 | Text on C.R.T. control | 9-3 | |
9.6 | Cursor control | 9-4 | |
9.7 | Digital output | 9-4 | |
10. | SERVICE IN | NF ORMAT ION | 10-1 |
10.1 | Blockdiagram and memory map | 10-1 | |
10.2 | The multiprocessor system | 10-7 | |
10.3 | Explanation of signal names | 10-9 | |
10.4 | Circuit description | 10-10 | |
10.5
10.5.1 10.5.2 10.5.3 |
Description of the diagnostic software
Introduction Softkey selectable diagnostic software Hardware selectable diagnostic software |
10-25
10-25 10-25 10-27 |
|
10.6 | Service tools | 10-28 | |
10.7 | Parts list | 10-29 |
IV
This interface is a general purpose bus line interface according to the IEEE-488/IEC-625 and the RS232-C/V24 document by which the oscilloscope can be adapted to make communication possible with other IEEE-/IEC-bus and RS232-C/V24 compatible measuring instruments.
For more detailed information about the bus system refer to the PHILIPS INSTRUMENTATION SYSTEMS REFERENCE MANUAL 9499 997 00411.
For more detailed information about the functioning of the hardware of the interface refer to the SERVICE INFORMATION, chapter 10 of this manual.
This handbook has been designed to enable you to use the utmost potential of this option and to answer your questions concerning programming the oscilloscope and how to connect the system to an IEEE controller or to a serial interface.
If you have just received your option, read chapter 2. (INSTALLATION INSTRUCTIONS) before you attempt to operate the instrument. This chapter contains initial installation information and precautions.
Then you can become familiar to the programming of the instrument by reading and following the examples in chapter 8 of the manual.
The best way to feel at ease with the system is to sit down with the programming manual chapter 7 PROGRAMMING CODES, type in the simple driver program (described in section 8.2) and actually key in the commands from chapter 7 or the examples provided in chapter 8.
It won't take long to become familiar with the programming of the oscilloscope and it is well worth the time you invest to obtain a more complete understanding of the "Remote Controlling" of your oscilloscope.
A number of different functions are covered by the term INTERFACE. They cover the most applicable instrumentation interfaces.
Data and communication protocol aspects are slightly described in these chapters.
These descriptions to a large extent are independent of the lower level functions, as these are laid down in the IEC-625 and IEEE- 488 standards or by the V24 and RS232-C data communication standards.
NOTE: Installation should be carried out by qualified personnel only.
Check the contents of the shipment for completeness and note whether any damage has occured during transport. If the contents are incomplete, or there is damage, a claim should be filed with the carrier immediately, and the PHILIPS Sales or Service organisation should be notified in order to facilitate the repair or replacement of the interface.
The following parts should be included in the shipment:
- 1 plug-in printed circuit board.
Check that all jumpers (8 pcs) on the plug-in printed circuit board are positioned as indicated in figure 2.1.
Figure 2.1 Position of the jumpers.
WARNING: The removal of covers is likely to expose live parts, and also accessible terminals may be live. The instrument shall be disconnected from all voltage sources before any installation during which the instrument will be opened. If afterwards any adjustment, maintenance or repair of the opened instrument under voltage is inevitable, it shall be carried out only by a skilled person who is aware of the hazards involved. Bear in mind that capacitors inside the instrument may still be charged even if the instrument has
- Switch the POWER ON-OFF switch to OFF.
- Disconnect the oscilloscope from the mains supply.
been separated from all voltage sources.
The instrument is protected by three covers: a front protection cover, a top cover and a bottom cover. To facilitate the removal of the instrument's covers, first put the front protection cover in position.
Then proceed as follows:
Figure 2.2 Removing the rear feet.
For installation of the printed circuit boards and the cables see also figure 2.3.
Proceed as follows:
Figure 2.3 Installation of boards and cables.
Various settings, such as address for IEEE-488 or baud rate for RS232-C, should be done via the softkeys. Therefore, refer to section 3.3 of this manual.
This chapter outlines the procedures and precautions necessary for operating the additional features, provided by this option. It identifies and briefly describes the functions of the front panel controls and indicators, and explains the practical aspects of operation to the operator. For the use of the explanation structure, please refer to chapter 4.2.1 of the operating manual of the oscilloscope.
After the oscilloscope has been connected to the mains (line) voltage in accordance with Section 3.2.1. and 3.2.2. of the operating manual of the oscilloscope it can be switched on with the POWER ON/OFF switch on the front panel. The associated POWER indicator lamp is adjacent to the POWER ON/OFF switch.
Having switched on the oscilloscope, a power-up routine is performed after which the instrument is ready for use.
When switching on the instrument, note that the internal microprocessor of the oscilloscope automatically starts a test for a number of internal circuits.
If during this test a circuit is found to be faulty, the test stops and this will be indicated as follows:
The instrument fails to operate normally.Some, but not all of the indicator lamps light.
If this occurs, it is recommended to switch off the oscilloscope and switch it on again after a few seconds.
IMPORTANT: If the fault condition persists, contact your local PHILIPS service department.
If the system blocks during operation, it may be due to extremely high static voltages. In this event, an automatical reset of the internal microprocessor system is performed and the operation of the instrument is restored.
If no back up batteries are installed and the oscilloscope is switched on, an automatic AUTO-SET action is performed.
With back-up batteries installed, the oscilloscope settings at the moment of switching off are restored and the oscilloscope starts up with the same setting.
The option adds the following features to the oscilloscope:
The text OPTION>, displayed next to softkey 8 in the main DISPLAY menu, appears at the moment that the oscilloscope knows that an option is installed. Depending on the position of the option in the mainframe of the oscilloscope (slot A7 or AlO) the text INTERFACE is displayed in the textfield belonging to softkey 1 or 5 in the DISPLAY OPTION 1 menu.
Option settings can be done via the main DISPLAY menu of the oscilloscope when the text OPTION> is displayed next to softkey 8. Selecting this function by pressing softkey 8, will give the main option menu DISPLAY OPTION 1.
Figure 3.1 Main option menu DISPLAY OPTION 1.
In case this option is installed, and it is the only one in the oscilloscope, the option name for OPTION 1 will be INTERFACE and the option name for OPTION 2 will not be displayed.
Note that options always are installed, starting from slot A7 in the main frame (see chapter 2 INSTALLATION). The next page gives an overview of the menu structure behind the OPTION> softkey.
3-2
Figure 3.2 Menu structure behind the OPTION softkey.
After pressing the softkey OPTION in the main DISPLAY menu, menu DISPLAY OPTION 1 is displayed and the possible options can be selected.
1 Optionname> (name of the installed option in slot A7)
With this softkey the option functions can be selected for the option in slot A7.
2 --
3 --
4 --
5 Optionname> (name of the installed option in slot A10)
With this softkey the option functions can be selected for the option in slot AlO.
SINCE THIS MANUAL DEALS WITH THE OPTION PM8956A ONLY INTERFACE FUNCTIONS ARE DISCUSSED.
If INTERFACE is selected in menu DISPLAY OPTION 1, the OPTION INTERFACE menu is displayed and all the features provided by the option can be activated. The softkey text lines and the softkeys of the oscilloscope are switched to the option. The lowest line of the trace area will now show the current date and time (of the real time clock).
1/5 1 IEEE 488>
/ | |
---|---|
OPTION
LEEE 488 |
|
TALK ONLY | 1 |
LIST ONLY | 2 |
ADDRESSED | 3 |
ENTER > | 4 |
Address:xx | |
5 | |
6 | |
7 | |
RETURN | 8 |
Selecting IEEE 488> leads to another menu: OPTION IEEE 488, where the interface parameters for IEEE communication can be defined.
1/5 1 1 TALK ONLY
Pressing the softkey TALK ONLY defines the oscilloscope to act as a talker on the bus system. This is indicated by an intensified text TALK ONLY (note that there can only be one talker on the bus system at a given time).
1/5 1 2 LIST ONLY
Pressing the softkey LIST ONLY defines the oscilloscope to act as a listener on the bus system. This is indicated by an intensified text LIST ONLY.
3-8
1/5 1 3 ADDRESSED
Pressing the softkey ADDRESSED, defines the oscilloscope to act as a talker as well as a listener indicated by an intensified text ADDRESSED.
NOTE: The text ENTER and Address:xx is only visible if the function ADDRESSED is selected.
1/5 1 4 ENTER>
Pressing this softkey selects the ENTER IEEE ADDRESS. Now a new address can be entered by using the numeric keyboard on the front panel of the oscilloscope. Any address between 0 and 31 can be entered and will be displayed in the textline with ? and in the textline Address:xx in the OPTION IEEE 488 menu.
1/5 1 1/5 1/5 1 1/5 1/5 1 CLEAR This function clears the already entered address, which is displayed in the textfield ?. 1/5 1 4 8 EXECUTE Pressing this softkey stores the entered IEEE address and returns the system to the OPTION IEEE488 menu. If EXECUTE is pressed after CLEAR, the previously programmed value remains. 1/5 1 1/5 1
Returns the system to the menu OPTION INTERFACE.
1/5 2 RS232-C>
Pressing the softkey FRAME selects the RS232-C FRAME menu where the serial communication parameters like the number of stop bits, the number of data bits and the parity can be defined.
1/5 2 1 STOP BIT
Defines 1 STOP bit in the data frame indicated by an intensified text 1 STOP BIT.
1/5 2 1 2 2 STOP BIT
Defines 2 STOP bits in the data frame indicated by an intensified text 2 STOP BIT.
1/5 2 1 3 7 DATA BIT Defines 7 DATA bits in the data frame indicated by an intensified text 7 DATA BIT. 1/5 2 1 4 8 DATA BIT Defines 8 DATA bits in the data frame indicated by an intensified text 8 DATA BIT. 1/5 2 1 5 ODD Defines an odd parity (this means an odd number of "ones" in the data part of the frame) indicated by an intensified text ODD. 1/5 2 1 EVEN 6 Defines an even parity (this means an even number of "ones" in the data part of the frame) indicated by an intensified text EVEN. 1/5 2 1 NO Defines NO parity indicated by an intensified text NO. 1/5 2 RETURN 1 8 Pressing this softkey will store the entered frame
Pressing this softkey will store the entered frame format and the system returns to the previous menu OPTION RS232-C.
1/5 2 2 OUTP SPEED>
RS232-C OUTP SPEED
1
2
3
4
6
8
Range:
Baudrate
75 .. 19k2
UP DOWN
RETURN
After selecting OUTP SPEED>, the output baudrate of the serial interface can be defined. The available range for baudrates is: 75, 110, 150, 300, 600, 1200, 2400,
4800, 9600 and 19200 baud.
The actual output speed is displayed in the textfield ?.
1/2 | 2 | 2 | T | |
---|---|---|---|---|
1/5 2 --
3-10
1/5 2 1/5 2 4 1/5 2 5 UP Pressing this softkey will increase the actual baudrate with one step in the range until the maximum baudrate of 19200 baud is reached. 1/5 2 2 6 DOWN Pressing this softkey will decrease the actual baudrate with one step in the range until the minimum baudrate of 75 baud is reached. --1/5 2 1/5 2 8 RETURN Pressing this softkey, returns the system to the
Pressing this softkey, returns the system to the previous menu OPTION RS232-C.
RS232-C INP SPEED Range: 1 Baudrate 2 75..19k2 3 New speed: 4 UP 5 DOWN 6 -- 7 RETURN 8
The input baudrate of the serial interface can be defined. The available range for baudrates is:
75, 110, 150, 300, 600, 1200, 2400, 4800, 9600 and 19200 baud.
The actual input speed is displayed in the textfield ?.
1/5 | 2 | 3 | 1 | |
---|---|---|---|---|
1/5 | 2 | 3 | 2 | |
1/5 | 2 | 3 | 3 | |
1/5 | 2 | 3 | 4 | |
1/5 | 2 | 3 | 5 | UP |
Pressing this softkey will increase the actual input speed with one step in the range until the maximum baudrate of 19200 baud is reached.
1/5 | 2 | 3 | 6 | DOWN |
---|---|---|---|---|
Pressing this softkey will decrease the actual
input speed with one step in the range until the minimum baudrate of 75 baud is reached. |
||||
1/5 | 2 | 3 | 7 | |
1/5 | 2 | 3 | 8 | RETURN |
Pressing this softkey, returns the system to the previous menu OPTION RS232-C. | ||||
NOTE: The textline SDPISPOSP, displayed in the
menu OPTION RS232-C stands for Stop bits, Data bits, Parity, Input SPeed and Output SPeed (see also section 5.4). |
||||
28E1K2075 means: | ||||
2 Stop bits, 8 Data bits, Even Parity, 1200
baud input speed and 75 baud output speed. |
||||
1/5 | 2 | 4 | ||
1/5 | 2 | 5 | ||
1/5 | 2 | 6 | ||
1/5 | 2 | 7 | ||
1/5 | 2 | 8 | RETU | RN |
Pres:
prev: |
sing this softkey returns the system to the
ious menu OPTION INTERFACE. |
|||
1/5 | 3 | |||
1/5 | 4 | |||
1/5 | 5 | USER | TEXT | > |
OPTI
USER CURS CURS CLEA U L UPPE LOWE RE |
ON
TEXT OR => OUT OR <= R LINE M CR CONF CR CONF CC CONF CTURN |
With function USER TEXT it is possible to
define a text of 80 characters. This text will be displayed on the bottom text area of the C.R.T. screen, and is only visible if the USER TEXT menu is activated. The user text can be read by the interfaces. The user text line is split up in two parts of 40 characters on the bottom text area of the C.R.T. screen. The actual cursor position is indicated with an When the cursor moves over already existing text, the cursor position is indicated by an intensified character in the text line. There are three character types available to select. |
||
1/5
1/5 1/5 1/5 1/5 1/5 1/5 |
1/5 2
1/5 2 1/5 2 1/5 2 1/5 2 1/5 2 1/5 2 1/5 2 1/5 3 1/5 4 1/5 3 1/5 4 1/5 5 |
1/5 2 3
1/5 2 3 1/5 2 3 1/5 2 3 1/5 2 3 1/5 2 6 1/5 2 6 1/5 2 7 1/5 2 6 1/5 2 7 1/5 2 8 1/5 2 8 1/5 3 1/5 4 1/5 4 1/5 5 USER OPTION USER TEXT CURSOR <= RUB OUT CURSOR <= CLEAR LINE U L M UPPER CONF LOWER CONF MISC CONF RETURN |
1/5 2 3 6 1/5 2 3 7 1/5 2 3 8 1/5 2 3 8 1/5 2 3 8 1/5 2 5 1/5 2 6 1/5 2 7 1/5 2 7 1/5 2 8 RETUR 07100 USER TEXT CURSOR => [] 0/5 4 [] [] 1/5 3 [] [] 0/5 USER TEXT [] 0/5 J [] [] 1/5 4 [] [] 0/5 USER TEXT [] [] 0/5 USER TEXT [] [] 0/5 UL M [] [] 0/5 UL M [] [] 0/7 [] |
3-12
The actual available upper case character is displayed in the softkey text field "U".
To select another uppercase character press the AMPL/DIV UP/DOWN control of channel A, on the front panel of the oscilloscope. Pressing the left side of the UP/DOWN control decreases the alfabetic order (A...Z). Pressing the right side increases the order. There is an automatic wrap around from Z -> A and from A -> Z.
from a -> z.
The actual available lower case character is displayed in the softkey textfield "L". To select another lower case character press the AMPL/DIV UP/DOWN control of channel B on the front panel of the oscilloscope. Pressing the left side of the UP/DOWN control decreases the alfabetic order (a...z). Pressing the right side increases the order. There is an automatic wrap around from z -> a and
The actual available miscellaneous character is displayed in the softkey textfield "M". To select another miscellaneous character press the TIME/DIV UP/DOWN control on the front panel of the oscilloscope.
The following characters are available:
0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
---|---|---|---|---|---|---|---|---|---|
: | : | < | = ' | > | ? | 0 | [ | ] | |
^ | , | • | { | } | 1 | 11 | # | ||
Ş | % | & | , | ( | ) | * | + | , | - |
• | / |
Pressing the left side of the TIME/DIV UP/DOWN control decreases the position in the range showed above, pressing the right side increases the order. There is a wrap around from / to Ø and Ø to /.
Figure 3.3 User text (also applicable for PM3340).
1/5 5 1 CURSOR =>
Every time the CURSOR => softkey is pressed, the cursor position advances with one step in the user text lines until the last position is reached (position 40 in the second text line).
1/5 5 2 RUB OUT
The previously entered character is rubbed out. The cursor moves one position backwards.
1/5 5 3 CURSOR <=
Every time the CURSOR <= softkey is pressed, the cursor position is moved to the left with one step until the first position is reached. (position 0 in the first text line).
1/5 5 4 CLEAR LINE
The totally entered text will be cleared when pressing this key. So all 80 characters.
1/5 5 5 UPPER CONF
Pressing this key stores the character, represented at that moment on the position "U" in the textline at the current cursor position on the C.R.T. screen (uppercase character).
1/5 5 6 LOWER CONF
Pressing this key stores the character, represented at that moment on the position "L" in the textline at the current cursor position on the C.R.T. screen (lowercase character).
1/5 5 7 MISC CONF
Pressing this key stores the character, represented at that moment on the position "M" in the textline at the current cursor position on the C.R.T. screen.
1/5 5 8 RETURN
Returns the system to the previous menu OPTION INTERFACE.
NOTE: When pressing the CONFirm function (U, L or M) the cursor advances one position.
1/5 6 CALIBRATE>
/ | |
---|---|
OPTION | |
CALIBRATE | |
Last date: | 1 |
2 | |
Current | 3 |
date: | 4 |
CALIBRATE | 5 |
6 | |
7 | |
RETURN | 8 |
The function CALIBRATE offers the possibility to write the calibration date into the backup memory of the oscilloscope, indicating the last calibration and/or service date.
Pressing this key enters the current date in the memory. The last stored date will be changed into the current date.
1/5 6 8 RETURN
Returns the system to the previous menu OPTION INTERFACE.
1 |
---|
1
2 |
2 |
2 |
4 |
5 |
6 |
7 |
8 |
7 With the CLOCK function it is possible to set the date and the time of the real time clock via the OPTION CLOCK menu.
The display of the TIME and the DATE is a part of the display of register R3 and can be shifted over the screen, using the Y-POSITION control.
1/5 7 SET TIME>
7 1/5 7 5 --1/5 7 1 6
1/5 7
1/5 7
CLEAR
The already entered time setting is cleared when this softkey is pressed.
Pressing this softkey stores the entered time and returns the system to the previous menu OPTION CLOCK.
1/5 7 2 TIME
This softkey defines the display of the TIME on the screen (ON/OFF), indicated by an intensified text TIME. TIME is a toggle function: the TIME is displayed in the lower right corner of the C.R.T. screen, even if no OPTION MENU is selected.
1/5 7 3 --
1/5 7
1/5 7 4 ---
5
1/5 7 5 SET DATE>
Pressing the softkey SET DATE> results in the ENTER DATE menu. Now it is possible to enter the date via the ENTER keyboard on the front. 1 Enter year Enter: year уу month dav 2 month mm like: 3 day dd yy.mm.dd Leap year correction is implemented. 5 CLEAR 6 7 8 EXECUTE 1
1/5 | 7 | 5 | 2 | |
1/5 | 7 | 5 | 3 | |
1/5 | 7 | 5 | 4 | |
1/5 | 7 | 5 | 5 | |
1/5 | 7 | 5 | 6 | CLEAR |
The already entered date setting is cleared when
this softkey is pressed |
||||
1/5 | 7 | 5 | 7 |
1/5 7 5 8 EXECUTE
Pressing this softkey stores the entered date and returns the system to the previous menu OPTION CLOCK.
1/5 7 6 DATE
This softkey defines the display of the DATE on the screen (ON/OFF), indicated by an intensified text DATE. DATE is a toggle-function. The DATE is displayed in the lower right corner of the C.R.T. screen, even if no OPTION menu is selected.
1/5 7 7 --
1/5 7 8 RETURN
Returns the system to the OPTION INTERFACE menu.
1/5 8 RETURN
Returns the system to the DISPLAY OPTION 1 menu.
Returns the system to the main DISPLAY menu of the oscilloscope.
The oscilloscope functions are now extended with DIGITAL PLOT and DIGITAL PRINT modes like the REGISTER PLOT, the REGISTER PRINT, the REGISTER AUTO PLOT, the REGISTER AUTO PRINT, the SCREEN PLOT and the SCREEN PRINT mode.
REGISTER PLOT and REGISTER PRINT stands for direct plotting or printing of register contents without the influence of display functions like for example Y-POS, Y-MAGNIFY, X-POS, X-EXPAND, X-MAGNIFY, INVERT or DOTS.
SCREEN PLOT and SCREEN PRINT stands for plotting or printing of register contents including the influence of the above mentioned display functions.
NOTE: 1) To assure a good plotter/printer-oscilloscope initialisation for the serial interface, first switch on the plotter/printer and then the oscilloscope. Also use this way of initialisation when you change the plotter language. (HPGL - PHILIPS and vice versa).
2) When for some reason the interface initialisation went wrong, and the interface is blocked, a message
DIGITAL output activated, but no output on selected interface
is displayed on the screen of the oscilloscope.
In this case:
1: Plotter pens:
Pen 1 is used for the data and text of channel A. Pen 2 is used for the data and text of channel B. Pen 3 is used for texts which are not related to channel A or to channel B. Pen 4 is not used. Pen 5 is used for the graticule, the time and the date.
2: Time and date:
The time and the date are plotted above the upper right corner of the graticule.
3: Text:
The FULL text of the selected register is always plotted and is placed below the lowest graticule line. Settings like CHANNEL IDENT, A versus B and INVERT (selected via the DISPLAY menu) are taken into account during the plot.
4: Plot size:
The data plot area is 10 div. (H) x 10 div. (W).
The plot size (including text) can be changed (via menu PLOTTER SETUP) with a multiplication factor. With a factor of 1, each division is 1 cm (H) x 1 cm (W). This factor has a range of 0.5 to 2.0 with a resolution of 0.1. The default Y-POS, Y-MAGNIFY, X-POS, X-EXPAND and X-MAGNIFY are taken into account on the plot-out.
5: Quadrant:
The plot quadrant on the plot medium can be selected via the menu PLOTTER SETUP.
6: Grid:
The grid to be plotted can be selected via the menu PLOTTER SETUP.
7: Plot output direction:
The plot output can be directed (via menu PLOTTER SETUP) to either the IEEE interface (which is set automatically to TALK ONLY during the plot time) or the RS232-C interface.
8: Signal processing:
The signal to be plotted, can be processed before plotting, to increase the plot speed. This means that vertical changes in the signal of about 5 bit will not result in a real plot action. Only if a dot is out of this range, a line is plotted (starting at the last plotted dot) to just before this point, after which the signal processing algorithme starts again. This may introduce some distortion. Signal processing is carried out if SMOOTH (PM3320A) or AVERAGE C=4 (PM3340) is selected. Signal processing is not posssible if A versus B is selected.
Only dots, without dot join, can be plotted. Between every two dots a pen-up and pen-down is given. This plot mode is carried out if DOTS is turned on. This mode is recommended for eye-patterns.
1: Plotter pens:
Pen 1 is used for the data and text of channel A. Pen 2 is used for the data and text of channel B. Pen 3 is used for texts which are not related to channel A or to channel B. Pen 4 is not used. Pen 5 is used for the graticule, the time and the date.
2: Time and date:
The time and the date are plotted above the upper right corner of the graticule.
3: Text:
The plotting of FULL text depends on whether the FULL text is selected for display on the C.R.T. screen or not. FULL text is placed below the lowest graticule line. Settings like CHANNEL IDENT, A versus B and INVERT (selected via the DISPLAY menu) are taken into account during the plot.
4: Plot size:
The data plot area is 10 div. (H) x 10 div. (W).
The plot size (including text) can be changed (via menu PLOTTER SETUP) with a multiplication factor. With a factor of 1, each division is 1 cm (H) x 1 cm (W). This factor has a range of 0.5 to 2.0 with a resolution of 0.1. The default Y-POS, Y-MAGNIFY, X-POS, X-EXPAND and X-MAGNIFY are taken into account on the plot-out.
5: Quadrant:
The plot quadrant on the plot medium can be selected via the menu PLOTTER SETUP.
6: Grid:
The grid to be plotted can be selected via the menu PLOTTER SETUP.
7: Plot output direction:
The plot output can be directed (via menu PLOTTER SETUP) to either the IEEE interface (which is set automatically to TALK ONLY during the plot time) or the RS232-C interface.
3-22
The signal to be plotted, can be processed before plotting, to increase the plot speed. This means that vertical changes in the signal of about 5 bit will not result in a real plot action. Only if a dot is out of this range, a line is plotted (starting at the last plotted dot) to just before this point, after which the signal processing algorithme starts again. This may introduce some distortion. Signal processing is carried out if SMOOTH (PM3320A) or AVERAGE C=4 (PM3340) is selected, Signal processing is not possible if A versus B is selected.
9: Dots plot:
Only dots, without dot join, can be plotted. Between every two dots a pen-up and pen-down is given. This plot mode is carried out if DOTS is turned on. This mode is recommended for eye-patterns.
Pen 1 is used for the data and text of register RØ. Pen 2 is used for the data and text of register R1. Pen 3 is used for the data and text of register R2. Pen 4 is used for the data and text of register R3. Pen 5 is used for the graticule, the time and the date.
The time and the date are plotted above the upper right corner of the graticule.
3: Text:
The plotting of FULL and/or REDUCED text depends on whether the FULL and/or REDUCED text is selected for display on the C.R.T. screen or not.
4: Plot size:
The data plot area is 8 div. (H) x 10 div. (W).
The plot size (including text) can be changed (via menu PLOTTER SETUP) with a multiplication factor. With a factor of 1, each division is 1 cm (H) x 1 cm (W). This factor has a range of 0.5 to 2.0 with a resolution of 0.1.
5: Quadrant:
The plot quadrant on the plot medium can be selected via the menu PLOTTER SETUP.
6: Grid:
The grid to be plotted can be selected via the menu PLOTTER SETUP.
The plot output can be directed (via menu PLOTTER SETUP) to either the IEEE interface (which is set automatically to TALK ONLY during the plot time) or the RS232-C interface.
8: Signal processing:
The signal to be plotted, can be processed before plotting, to increase the plot speed. This means that vertical changes in the signal of about 5 bit will not result in a real plot action. Only if a dot is out of this range, a line is plotted (starting at the last plotted dot) to just before this point, after which the signal processing algorithme starts again. This may introduce some distortion. Signal processing is carried out if SMOOTH (PM3320A) or AVERAGE C=4 (PM3340) is selected. Signal processing is not possible if A versus B is selected.
9: Dots plot:
Only dots, without dot join, can be plotted. Between every two dots a pen-up and pen-down is given. This plot mode is carried out if DOTS is turned on. This mode is recommended for eye-patterns.
The time and the date are printed above the upper right corner of the graticule.
2: Text:
The FULL text of the selected register is always printed and is placed below the lowest graticule line. Settings like CHANNEL IDENT, A versus B and INVERT (selected via the DISPLAY menu) are taken into account during the print.
3: Print size:
The data print area is 10 div. (H) x 10 div. (W), which corresponds to 10 x 10 cm approx. This size cannot be changed.
4: Grid:
The grid to be printed can be selected via the menu PRINTER SETUP.
5: Print output direction:
The print output can be directed (via menu PRINTER SETUP) to either the IEEE interface (which is set automatically to TALK ONLY during the print time) or the RS232-C interface.
6: Dots print:
Only dots, without dot join, can be printed. This print mode is carried out if DOTS is turned on. This mode is recommended for eve-patterns.
The time and the date are printed above the upper right corner of the graticule.
2: Text:
The FULL text of the selected register is always printed and is placed below the lowest graticule line. Settings like CHANNEL IDENT, A versus B and INVERT (selected via the DISPLAY menu) are taken into account during the print.
3: Print size:
The data print area is 10 div. (H) x 10 div. (W), which corresponds to 10 x 10 cm approx. This size cannot be changed.
4: Grid:
The printed grid type can be selected via the menu PRINTER SETUP.
5: Print output direction:
The print output can be directed (via menu PRINTER SETUP) to either the IEEE interface (which is set automatically to TALK ONLY during the print time) or the RS232-C interface.
6: Dots print:
Only dots, without dot join, can be printed. This print mode is carried out if DOTS is turned on. This mode is recommended for eye-patterns.
1: Time and date:
The time and the date are printed above the upper right corner of the graticule.
2: Text:
The printing of FULL and/or REDUCED text depends on whether the FULL and/or REDUCED text is selected for display on the C.R.T. screen or not.
3: Print size:
The data print area is 8 div. (H) x 10 div. (W), which corresponds to 8 x 10 cm approx. This size cannot be changed.
4: Grid:
The grid to be printed can be selected via the menu PRINTER SETUP.
5: Print output direction:
The print output can be directed (via menu PRINTER SETUP) to either the IEEE interface (which is set automatically to TALK ONLY during the print time) or the RS232-C interface.
6: Dots print:
Only dots, without dot join, can be printed. This print mode is carried out if DOTS is turned on. This mode is recommended for eye-patterns.
This menu can be selected via the SAVE/PLOT menu of the oscilloscope.
Via this menu tree it is possible to select the required plotter or printer, plot or print direction and plot size.
- Press pushbutton SAVE/PLOT, this results in the display of the SAVE/PLOT menu.
/ | ||
---|---|---|
PLOT
SELECT R0 R1 R2 R3 |
1
2 3 4 |
|
ANALOG
DIGITAL RELURN |
> | 5 6 7 8 |
If SELECT is selected, the PLOT SELECT menu, which now is extended with the function DIGITAL>, is displayed. DIGITAL> can now be selected after which a number of digital plot or print settings can be done.
ANALOG> as described in the operating manual of the oscilloscope, remains possible.
/ | |
---|---|
DIGITAL | |
SELECT | |
PLOTTERS > | |
PRINTERS > | 2 |
3 | |
4 | |
PLOT PRINT | 5 |
6 | |
RETURN | |
If DIGITAL is selected, the DIGITAL SELECT menu is displayed and the plotter or printer type to be used can be selected.
The DIGITAL PLOTTERS menu is displayed and different plotter types can now be selected.
PM8153/1 8 6 1 8 6 1 2 PM8153/6 8 6 3 PM8154 (only PHILIPS language, no HPGL) PM8155 (use HPGL only) 8 6 4 8 6 5 HP7475A 8 6 1 6 HP7550
6 1 1-6
operating the DOWN pushbutton.
A selection can be made between the IEEE and the RS232 interface as digital plotter output interface. The interface parameters for serial plotting have to be set accordingly via the OPTION INTERFACE menu.
8 6 1 1-6 8 RETURN
After pushing softkey RETURN, the DIGITAL PLOTTERS menu is displayed again.
After pushing softkey RETURN, the DIGITAL SELECT menu is displayed again.
8 6 2 PRINTERS>
DIGITAL
PRINTERS FX 80 > HP 2225 > |
|
---|---|
RETURN |
4
5 6 7 8 |
The DIGITAL PRINTERS menu is displayed and different printer types can now be selected.
8
6 2 1-2
After pushing one of the two printer select softkeys in the DIGITAL PRINTERS menu, the PRINTER SETUP menu is displayed.
8 6 2 1-2 2 6 1-2 3 GRID 01 8 1-2 4 GRID 2 NO A selection can be made between three grid types or NO grid. Grid 0 is a complete grid, consisting of border lines and vertical and horizontal grid lines. Grid 1 is a grid of border lines and centre vertical and horizontal grid lines. Grid 2 is a grid of only border lines. The selected grid type is displayed intensified. 8 2 1-2 5 6 8 6 1-2 6 8 6 1-2 7 IEEE RS232 A selection can be made between the IEEE and the RS232 interface as digital printer output interface. The interface parameters for serial printing have to be set accordingly via the OPTION INTERFACE menu. 1-2 8 RETURN After pushing softkey RETURN, the DIGITAL PRINTERS menu is displayed again. 8 6 2 3 8 2
8 | 6 | 2 | 5 | |
---|---|---|---|---|
8 | 6 | 2 | 6 | |
8 | 6 | 2 | 7 | |
8 | 6 | 2 | 8 | RETURN |
After pushing softkey RETURN, the DIGITAL SELECT menu is displayed again. | ||||
8 | 6 | 3 | ||
8 | 6 | 4 | ||
8 | 6 | 5 | PLO | f PRINT |
A se
This plot The |
election can be made between plotting or printing.
s selection also determines if in the actual t/print menus PLOT or PRINT appears. selected option is displayed intensified. |
|||
8 | 6 | 6 | ||
8 | 6 | 7 | ||
8 | 6 | 8 | RET | JRN |
Aft
dis |
er pushing softkey RETURN, the PLOT SELECT menu is played again. | |||
8 | 7 | |||
8 | 8 | RETU | URN | |
List a false DETUDY the CAVE DIOT monu is |
After pushing softkey RETURN, the SAVE/PLOT menu is displayed again.
The REGISTER PLOT function can be selected via the SAVE/PLOT menu, if PLOT was selected before in the DIGITAL SELECT menu:
- Press pushbutton SAVE/PLOT, this results in the display of the SAVE/PLOT menu, which now is extended with the function DIGITAL>.
ANALOG> as described in the operating manual of the oscilloscope, is still possible.
6 DIGITAL>
A PLOT action can be interrupted by pushing softkey STOP. The SAVE/PLOT menu is then displayed again. During a plot action, it is not possible to switch to another softkey menu or to change any other function of the oscilloscope.
3-32
The REGISTER AUTO PLOT function can be selected via the SAVE/PLOT menu, if PLOT was selected before in the DIGITAL SELECT menu:
PLOT
AUTOMATIC |
|
---|---|
ANALOG >
DIGITAL > REIURN |
5
6 7 8 |
REGISTER AUTO PLOT is only selectable in the SINGLE-shot mode. (The text AUTO PLOT is not visible in an other horizontal mode).
In this mode, the contents of register RØ is automatically plotted each time that the memory contents is refreshed after a valid trigger signal.
If AUTO PLOT is selected, the PLOT AUTOMATIC menu, which now is extended with the function DIGITAL>, is displayed.
ANALOG> as described in the operating manual of the oscilloscope, remains possible.
/ | |
---|---|
T | |
AUTO PLOT
DIGITAL |
|
1 | |
2 | |
3 | |
4 | |
PLOT RØ | |
5 | |
6 | |
7 | |
STOP | 8 |
After selecting DIGITAL, the AUTO PLOT DIGITAL menu is displayed and the contents of register RØ is plotted. The plot size, the plot quadrant, the grid type and the plotter interface can be selected via the SELECT function of the SAVE/PLOT menu . During the PLOT action, the AUTO PLOT
DIGITAL menu is displayed and a message
* * PLOTTER ACTIVE * Changes are possible after plotter has stopped.
is displayed.
At the end of the DIGITAL AUTO PLOT action, menu PLOT AUTOMATIC is displayed again, and the instrument waits for another single shot acquisition to be plotted.
7 6 1 ---7 6 2 ---7 6 3 ---
7 6 4 -- 7 6 5 -- 7 6 6 -- 7 6 7 -- 7 6 8 STOP
A PLOT action can be interrupted by pushing softkey STOP. The PLOT AUTOMATIC menu is then displayed again. During a plot action it is not possible to switch to an other softkey menu or to change any other function of the oscilloscope.
The SCREEN PLOT function can be selected via the DISPLAY menu if PLOT was been selected before in the DIGITAL SELECT menu:
ANALOG> as described in the operating manual of the oscilloscope, remains possible.
6
6
6
6 6
8
STOP
After selecting DIGITAL, a copy of the screen is made on a digital plotter. During the PLOT action, the PLOT DIGITAL menu is displayed and a message
* * PLOTTER ACTIVE *
is displayed.
The settings made with the Y-POSITION control, the X-POSITION control and the X-EXPAND control remain.
At the end of the DIGITAL SCREEN PLOT action the menu DISPLAY PLOT is displayed again.
A PLOT action can be interrupted by pushing softkey STOP. The DISPLAY PLOT menu is then displayed again.
The REGISTER PRINT function can be selected via the SAVE/PLOT menu, if PRINT was selected before in the DIGITAL SELECT menu:
- Press pushbutton SAVE/PLOT, this results in the display of the SAVE/PLOT menu, which now is extended with the function DIGITAL>.
ANALOG> as described in the operating manual of the oscilloscope, is still possible.
6 DIGITAL>
A PRINT action can be interrupted by pushing softkey STOP. The SAVE/PLOT menu is then displayed again. During a print action, it is not possible to switch to another softkey menu or to change any other function of the oscilloscope.
The REGISTER AUTO PRINT function can be selected via the SAVE/PLOT menu, if PRINT was selected before in the DIGITAL SELECT menu:
/ | |
---|---|
PLOT | |
AUTOMATIC | |
2 | |
3 | |
4 | |
ANALOG > | 5 |
DIGITAL > | 6 |
7 | |
RETURN | 8 |
REGISTER AUTO PRINT is only selectable in the SINGLE-shot mode. (The text AUTO PLOT is not visible in an other horizontal mode).
In this mode, the contents of register RØ is automatically printed each time that the memory contents is refreshed after a valid trigger signal.
If AUTO PRINT is selected, the PLOT AUTOMATIC menu, which now is extended with the function DIGITAL>, is displayed.
ANALOG> as described in the operating manual of the oscilloscope, remains possible.
/ | |
---|---|
AUTO PRINT
DIGITAL |
|
1 | |
2 | |
3 | |
4 | |
PRINT RØ | |
5 | |
6 | |
7 | |
STOP | 8 |
After selecting DIGITAL, the AUTO PRINT DIGITAL menu is displayed and the contents of register RØ is printed. The grid type and the printer interface can
be selected via the SELECT function of the SAVE/PLOT menu .
During the PRINT action, the AUTO PRINT DIGITAL menu is displayed and a message
* * PRINTER ACTIVE * Changes are possible after printer has stopped.
is displayed.
At the end of the DIGITAL AUTO PRINT action, menu PLOT AUTOMATIC is displayed again, and the instrument waits for another single shot acquisition to be printed.
7 6 1 ---7 6 2 ---7 6 3 ---
--STOP
A PRINT action can be interrupted by pushing softkey STOP. The PLOT AUTOMATIC menu is then displayed again. During a print action it is not possible to switch to an other softkey menu or to change any other function of the oscilloscope.
The SCREEN PRINT function can be selected via the DISPLAY menu if PRINT was selected before in the DIGITAL SELECT menu:
ANALOG> as described in the operating manual of the oscilloscope, remains possible.
6 DIGITAL>
A PRINT action can be interrupted by pushing softkey STOP. The DISPLAY PLOT menu is then displayed again.
If PRINT is selcted in the DIGITAL SELECT menu (see figure 3.4), then the PLOT DIGITAL menu is called PRINT DIGITAL.
Figure 3.5 Extended display menu structure.
The IEC-bus interface is designed for interconnecting several instruments, programmable or non-programmable, to form a measuring system. International agreements on such a system (using byte serial, bit parallel operation) are defined in IEC Publication 625-1.
To simplify cabling and to allow for extension, the interface is organized as a bus-line system. All instruments are interconnected via a common set of 16 lines.
As the bus-line is common to all instruments, to communicate effectively the problems of interfacing have to be solved within the instruments themselves; i.e. they must be designed with inbuilt IECbus facilities. This enables the user to select the most suitable instruments for his system, regardless of make, knowing that interfacing is not a major problem.
These IEC-bus facilities to be described are the functional, electrical and mechanical requirements of instruments designed for connection to the interface, as defined in IEC Publication 625.
One other standard conforms to the IEC 625-standard in all respects except for the type of interface connector used (see Section 4.12 Mechanical specifications). This variant is the American standard LEEE-488, sometimes referred to as:
HP-IB HP Interface Bus.
GPIB General-Purpose Interface Bus.
IEC-bus compatible instruments:
To satisfy the necessary requirements, interface functions are built into the instrument as active circuits. These circuits are dependent on the role of the instrument in the system and are additional to thenormal device functions for which the instrument is primarily designed.
Basically, in any communication link there are:
Devices addressed to receive data. More than one listener device can be active on the bus interface at a given time.
Devices addressed to send data. Only one talker device can be active on the interface at a given time.
Instruments for addressing devices as talkers and listeners, also for sending special commands and control signals. In addition to its control function, a controller must have a talk function and, generally, a listen function.
The data byte transfer control, or "handshake" functions ensure that valid data is offered by the talker, that all listeners are ready to accept it, and also verifies that they have accepted it. The IEC interface includes other functions in addition to the above mentioned listen, talk and control functions.
NOTE: The terms, listener, talker and controller refer to selectable functions and any one device may be capable of being programmed to perform one or more of these functions, as shown in Fig. 4.1. For example, a device with a listener function is able to listen and is termed "listener" when addressed as a listener.
4-2
Figure. 4.1 Bus structure and interface capabilities.
The 16 bus-lines are divided into three functional groups:
8 data lines from the data-bus for multiline messages. 3 lines are used for data-byte transfer control (handshake lines). 5 lines are used for interface management.
The 8 bus-lines allocated for input/output data (DIO 1...8) are used for:
A data byte consists of 8 parallel data bits. Where more information is needed, a complete message may comprise several data bytes in series. The maximum rate of data transfer over this two-directional asynchronous bus-system is 1 Mbyte per second.
These 3 lines control the exchange of data bytes between devices. The lines are briefly defined as:
DAV DATA VALID (controlled by the source)
NRFD NOT READY FOR DATA (controlled by the acceptor)
NDAC NOT DATA ACCEPTED (controlled by the acceptor)
These handshake lines are activated to provide the necessary control whenever data bytes are sent over the 8 data-bus lines. They ensure that a source (generally a talker) regulates its speed to that of the slowest acceptor (generally a listener). During the transfer of a byte, the source handshake function in the interface section of a talker is active, and the acceptor handshake functions of listeners are also active.
The five lines of this group each have a specific control function between the controller and the other instruments in the system. Briefly the functions are as follows:
A system controller facility to enable instruments to be switched between local (front panel) control and remote control.
A controller facility to select either interface messages or device-dependent messages.
4-4
IFC INTERFACE CLEAR
A system controller facility to set the interface in a predefined state or to take over control in a multiple controller system.
SRQ SERVICE REQUEST
A device function to ask for attention from the controller.
EOI END OR IDENTIFY
Used by the talker to indicate the end of a multiple-byte transfer if ATN=0, or used by a controller to obtainresponse for parallel polling with ATN=1 (Identify message IDY=1).
The handshake procedure ensures the correct exchange of data-bytes between devices. It is the first level of the data transfer.
DAV DAta Valid (controlled by the source)
When DAV=LOW, this indicates that a message on the data-bus is correct and suitable for acceptance.
NRFD Not Ready For Data (controlled by the acceptors)
NRFD=high indicates that all instruments are ready to accept a new data-byte.
NDAC Not Data ACcepted
(controlled by the acceptors)
NDAC=high indicates that all listeners have acceptedthe databyte.
The handshake procedure is best explained by using an example of an addressed talker transferring data to a number of listeners.
Figure 4.2 Handshake procedure.
To ensure that the NRFD line is only high when all listeners are ready for data, the individual NRFD lines of each interface are connected as a so called wired-OR configuration; i.e. all instruments programmed as listeners have to signal "high" outputs before this line becomes high; this is also valid for the NDAC line.
The procedure is as follows:
For efficient operation, devices must be properly identified at any given time as either a data source (talker) or a data acceptor (listener). Each device is therefore given a coded address as a means of recognition by the active controller. An address consists of 7 bits.
DIO lines | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 |
---|---|---|---|---|---|---|---|---|
Address bits
Talk address Listen address |
x
x x |
Ъ7
1 0 |
Ъ6
О 1 |
b5 |
b4
— Dev |
b3
ice a |
b2
ddres |
b1
s⊥ |
The address of a device is determined by the position of the five address switches that select b5 to b1 (see ISO-code table, section 4.14 of this chapter). Switches b5 to b1 may not all be switched to 1 (address 31) because it means unlisten. It should also be noted that not all addresses are available, as some are already allocated to controllers. A controller addresses a particular instrument by placing the address code of that instrument on the 8 data lines and, at the same time, making ATN "true" (ATN=1). All devices on the bus compare the address code with their own address by using the message decoding function (part of the IEC interface in the device). The device having the same address as that on the data-bus performs the function of talker or listener, as defined by the address bits b6 and b7 of the address code. Therefore, for identification purpose it is necessary for instruments to have different addresses.
The correct oscilloscope address can be set by performing the following steps through the several menues, starting in main DISPLAY menu of the oscilloscope (see fig. 4.4).
ACTUAL MENU | STEP N | 0 | PRESSING | KEY # | NEW MENU | ||
---|---|---|---|---|---|---|---|
DISPLAY
DISPLAY OPTION 1 OPTION INTERFACE OPTION IEEE 488 OPTION IEEE 488 OPTION IEEE 488 OPTION IEEE 488 |
1
2 3 4 4 4 5 |
OPTION>
OPTIONNAME> IEEE 488> TALK ONLY LIST ONLY ADDRESSED ENTER |
8
1/5 1 2 3 4 |
DISPLAY OPTION 1
OPTION INTERFACE OPTION IEEE 488 OPTION IEEE 488 OPTION IEEE 488 OPTION IEEE 488 ENTER IEEE ADDRESS |
|||
ENTER IEEE ADDRESS | 6 |
Now it is possible to key-in the desired
address of the device, by entering the numbers via the numeric keyboard (2 positions). CLEAR: Clears the already entered address. |
|||||
ENTER IEEE ADDRESS
OPTION IEEE 488 OPTION INTERFACE DISPLAY OPTION 1 |
7
8 9 10 |
RETURN
RETURN RETURN RETURN |
8
8 8 8 |
OPTION IEEE 488
OPTION INTERFACE DISPLAY OPTION 1 DISPLAY |
Figure 4.3 Address setting in steps.
At delivery, or after switching-on an instrument without a memory backup battery, the oscilloscope is set to device address Ø8, listen and talk (addressed).
Figure 4.4 Address setting.
Any device in a system can use the service request line SRQ to ask for service by the controller, even when the data-bus lines are otherwise occupied. An instrument that is in an error- or alarm-condition may request service by sending the SRQ message.
Furthermore, some device activities may take several seconds and it may not be economical to block the whole system until these activities are completed. By using the SRQ facility, it is possible for the controller to continue with other activities and to interrupt these when the time consuming operation is finished. When the SRQ signal is activated by one of the devices, the controller can interrupt all other activities and attend to the device which is requesting for service. First of all it must detect which device gave the SRQ signal. This is done by means of the serial poll facility. As an alternative to interruption, periodic checking of the SRQ line by the controller program is also possible.
If the service request facility is not implemented, only periodic polling of all devices remains as an alternative.
Up to 14 devices can give service request via the SRQ line, providing they each have a service request facility in their IEC interface. Such a device must also have a talk function with a serial poll facility; its message decoding section must be capable of decoding the bus commands SPE (Serial Poll Enable) and SPD (Serial Poll Disable).
If an instrument is serial polled, it puts its status byte on the databus. In the status byte, DIO7 indicates whether an instrument has asked for service (SRQ=1). The other bits may give additional status information regarding the instrument polled; e.g. alarm, busy, ready.
Basically, the service request and serial polling is as follows:
Service can be requested for many reasons:
The device statusword reflects the status of the interface functions. However, since the interface functions can also be activated by device functions, the interface status may reflect some device condition; e.g. service request. The protocols relating to interface status data are covered by the relevant international standards.
The statusword can be read by programming a serial poll action.
Send UNlisten Send SPE (Serial Poll Enable) Make the oscilloscope TALKER Make controller LISTENER Read STATUS-word Send UNTalk Send SPD (Serial Poll Disable)
It may indicate incorrect process conditions (alarm or error status). See for error codes: section 7.4.
The device dependent bits in the STATUS-word of the oscilloscope specify the reasons for service request and/or reflect the status of the device functions.
The device statusword (8 bits) is built up as follows:
128 | 64 | 32 | 16 | 8 | 4 | 2 | 1 | Decimal value (equivalent) |
---|---|---|---|---|---|---|---|---|
D7 | D6 | D5 | D4 | D3 | D2 | D1 | DO | Data bits |
EXT | RQS | AB | BS | EF3 | EF2 | EF1 | EFO | Name |
EXT : Extension bit. This bit is not used and is always "Ø".
RQS : Request for service bit. This bit is set if the oscilloscope has generated a service request.
AB : Abnormal bit. This bit is set if an erroneous or alarm condition is detected. The status is specified in the bits EF3 - EFØ.
BS : Busy bit. This bit is set if the oscilloscope is measuring (busy with programmed action).
EF3 - EFØ : Status bits. The status reflected by these bits depends on the status of the AB bit.
EF1 : Not used.
EFØ : Not used.
If AB=1 they are defined as:
A service request with the Abnormal bit set, will override in a nonreversible way a status with the Abnormal bit cleared.
The following statuswords (decimal equivalent) are most usual: Nothing of interest is happening. URQ key is pressed. A non-masked event has happened. Power up passed successfully. Programming error. 100 There is valid data ready, but it cannot be transferred.
By waiting for a service request after a GROUP EXECUTE TRIGGER command the controller can check when the oscilloscope is ready with that measurement.
A number of events in the oscilloscope may generate a service request with the AB bit reset and with the EF2 bit set (error code 68). After having read the statusword after such a service request, the DEvice Status Register (DESR) can be read with the DESR? command to detect which event caused the service request. Reading the status will clear all bits.
The device status register (16 bits) is built up as follows:
Least significant byte:
128 | 64 | 32 | 16 | 8 | 4 | 2 | 1 | Decimal valu | e (equivalent) |
---|---|---|---|---|---|---|---|---|---|
| D7 | | D6 | | D5 | | D4 | | D3 | | D2 | | D1 | | D0 | Data bits | |
SB7 |
SB6 |
SB5 | SB4 | SB3 | SB2 | SB1 | SBO | Status Bit |
Most significant byte:
.. 2048 1024 512 256 Decimal value (equivalent)
| D7 | D6 | D5 | D4 | D3 | D2 | D1 | D0 | Data bits
SB15 SB14 SB13 SB12 SB11 SB10 SB9 SB8 Status Bit
Status bit meaning if set:
SB3: Autoset has finished
SB4: Auto-offset has finished.
SB5: Calibration has finished.
SB6: A mathematical calculation has started.
SB7: A mathematical calculation has finished.
SB8: A cursor measurement has started.
SB9: A cursor measurement has finished.
SB10: A single/multiple shot/scan has started.
SB11: A single/multiple shot/scan has finished.
SB12: Reserved for future expansions.
SB13: Reserved for future expansions.
SB14: Reserved for future expansions.
SB15: Reserved for future expansions.
These events can be disabled (masked) by the DEvice Status Enable Register (DESE). By setting the corresponding bit in the DESE register an event will not generate a service request.
After a service request due to an unmasked event (error code 68) further service requests with error code 68 are disabled until the DESR has been read.
To control the DESR and the DESE register the following commands are added:
DESE XXXXX DESE ? DESR ?
68.
These commands are described in chapter 7.
NOTE : Be carefull when using the DESE and DESR facility. Because of the continuous nature of calculations, measurements and the SAVE/STOP ON DIFFERENCE function, you may get again a service request right after you read the DESR. This may cause problems in application programs, which are not set up for this. A good advice may be to disable events before reading the DESR by programming DESE Ø after receiving a service request with error code
Determining the data transfer rate of the IEC bus is rather complex and depends upon the handshake timing of the acceptor and the source. In most applications however, the talker and listeners will cause a lot of overhead times, additional to the data transfer times of the handshake. This section only deals with handshake timing. To be able to calculate and to predict the time required to transfer a databyte (dab) over the bus, the handshake process itself has to be examined; the times in this process that are of interest to the transfer rate are to be determined. The handshake process between a source and a single acceptor is shown in fig. 4.5.
A source declares its sent data valid (DAV = low) at the moment that the databyte is stabilized on the DIO-lines and the acceptor is ready to receive a databyte (NRFD = high). At the moment that the DAV message becomes true the acceptor will respond to it and starts the input of the databyte; it will load the byte into its input buffer. At the moment that the input process is terminated, the databyte is accepted. This is indicated on the handshake bus by the NDAC-line becoming high (DAC=1).
The DAC-message only indicates that the databyte is accepted. The DACmessage does not indicate that the acceptor is ready again to accept the next databyte. The receiving device has first to implement the accepted byte before it is able to receive a next character; a certain time may be required for printing the received character or for implementing and executing the command (if the received character is to be regarded as control data).
Furthermore, the DAC-message indicates to the source that it may remove the byte from the databus and can send the next databyte. Upon receipt of this DAC-message, the source declares its data invalid (DAV=0) and removes the data from the bus. The source will start a procedure to pass the next databyte to the bus. After this new databyte has been transferred to the bus, a certain settling time is required to stabilize the signals on the DIO-lines. The source is ready to start a new handshake cycle after this settling time. If the acceptor device had already completed the implementation of the previous databyte at this time and is ready to receive the next databyte (RFD=1), the source will declare its new data valid: the handshake cycle starts again.
Figure 4.5 Data transfer time.
In the situation described above the source takes more time to pass and settle the next databyte to the bus than the acceptor requires to implement the previous input databyte.
It is obvious that in this case the data transfer rate is determined by the acceptor as well as by the source. The total transfer time equals the time required for input of the data plus the time required and settle the next data to the bus.
In reverse, if the acceptor device takes more time to implement the data than the source takes to pass and settle the data, the data transfer rate is only determined by the acceptor device. The total transfer time equals the time required for input of data plus the time needed to implement this data. Thus an increase of the source speed will not increase the datatransfer rate at all.
-Trd starts at the moment that the acceptor sets NDAC false.
Figure 4.6 Timing diagram.
Data transfer in DATA TYPE DECIMAL mode:
Source Handshake Oscilloscope ---> Controller
Tac = Controller depending Trd = Controller depending Tlst = < 150 ms Tsc = < 10 us (see figure 4.6)
Example:
DAT ?
Figure 4.7 Source handshake timing.
Data bytes
Figure 4.8 Source handshake timing.
Example:
DAT ....
Figure 4.9 Acceptor handshake timing.
Data bytes
Figure 4.10 Acceptor handshake timing.
Data transfer in DATA TYPE BINARY mode:
Source Handshake Oscilloscope ---> Controller
Tac = Controller depending Trd = Controller depending Tlst = < 150 ms Tsc = < 6 us
Example:
DAT ?
Data bytes
Figure 4.12 Source handshake timing.
Acceptor HandshakeController ---> OscilloscopeTac = < 3 us (see figure 4.6)</td>Trd = < 6 us (see figure 4.6)</td>Tlst = Controller dependingTsc = Controller depending
Example:
DAT ....
Figure 4.13 Acceptor handshake timing.
Data bytes
Figure 4.14 Acceptor handshake timing.
DATA_TYPE DECIMAL mode: (worst case if the controller does not limit the speed)
Example:
The transfer rate = 166 kb/s (worst case excluding the set up time of 150 ms).
Interface
function |
Identification code | Description |
---|---|---|
Source handshake
Acceptor handshake |
SH1
AH1 |
Complete capability
Complete capability - Basic talker - Serial poll - Talk only - Unaddress if MLA |
Listener function | L3 |
- Basic listener
- Listen only - Unaddress if MTA |
Service request | SR1 | Complete capability |
Remote local | RL2 | No local lock out |
Device clear | DC1 | Complete capability |
Device trigger | DT 1 | Complete capability |
Parallel poll | PPO | No capability |
Controller | CO | No capability |
The signal on the interface bus-lines are standardized in negative logic.
"high" | state > 2 V | 0 false |
---|---|---|
"low" | state < 0,8 V | l true |
Open collector driven circuits are used for the BUS signals.
The mechanical characteristics of the IEC interface are briefly outlined in this section. For more detailed information, refer to IEC Publication 625-1, Section 4 Mechanical Specifations, clauses 25 or 29.
The IEC-bus cables are provided with 25-pole connectors, type MIL-C-24308. A plug and receptacle combined design allows cables to be stacked together in piggyback fashion and secured by a locking mechanism.
For the oscilloscope the American variant of the IEC system (the IEEEbus), the 24-pole micro-ribbon, connectors (Amphenol or Cinch) is used. The receptacle type connector is located on the instruments rear side.
4-24
To ensure correct system operation, the cables for the interconnection of instruments must comply with the specification laid down in IEC-625. The cable should contain an overall shield and at least 24 conductors, of which 16 shall be used for signal lines and the balance used for logic ground returns.
Each of the signals: DAV, NRFD, NDAC, EOI, IFC, ATN, REN and SRQ, shall be a twisted pair together with one of the logic ground wires. The maximum capacitance existing between any signal line and all other lines connected to ground shall be 150 pF per meter.
IEC-BUS | SIGNAL LINES | IEEE-BUS | ||
1 | DIO 1 | 1 | ||
2 | DIO 2 | 2 | ||
3 | DIO 3 | 3 | ||
4 | DIO 4 | 4 | ||
14 | DIO 5 | 13 | ||
15 | DIO 6 | 14 | ||
16 | DIO 7 | 15 | ||
17 | DIO 8 | 16 | ||
B .7.1 | 17 | |||
5 | REN |
17
r |
||
150 01 | 6 | EOI |
)
( |
|
160 03 | 7 | DAV | 7 | |
8 | NRFD | 8 | ||
9 | TEC |
0
0 |
||
SPO | 10 | |||
ATN | 니니 | |||
12 | AIN | |||
13 | Shield | 12 | ||
18 | Gnd (REN) | - | | ||||||||||||||||||||||||||||||||||||| | |
230 010 | 19 | Gnd (EOI) | | _ | | |||2 |
20 | Gnd (DAV) | 18 | ||
21 | Gnd (NRFD) | 19 | ||
013 | 22 | Gnd (NDAC) | 20 | |
23 | Gnd (IFC) | 21 | ||
24 | Gnd (SRQ) | 22 | ||
25 | Gnd (ATN) | 23 | ||
MAT 2954 | - | Gnd Logic | 24 |
Figure 4.15 IEC-625-bus connector.
Figure 4.16 IEEE-488-bus connector.
MAT 2955
4-26
Type of interface |
ANSI/IEEE
Std.488-1978 |
|
-Connector | RFI/EMI shielded |
Amphenol type 57LE-20240-
7700D35G or similar, intermating with Amphenol 57FE series receptacles. |
-Bus drivers | E2 |
Three-state
(true = 00,8 V; false = 25 V). |
-Interfacing
function reper- toire |
||
Source handshake | SH1 | Complete capability. |
Acceptor handshake | AH1 | Complete capability. |
Talker | Τ5 |
Basic talker : yes
Serial poll : yes Talk only : yes Unaddress if MLA: yes |
Listener | L3 |
Basic listener : yes
Listen only : yes Unaddress if MTA: yes |
Service request | SR1 | Complete capability. |
Remote local | RL2 | No local lock-out. |
Parallel poll | PPO | No capability. |
Device clear | DC1 | Complete capability. |
Device trigger | DT1 | Complete capability. |
Controller | CO | No capability. |
-Address | 030 | Software settable, through softkeys and menu. |
Indicator | CRT | In softkeys area. |
Default Address | 8 |
At delivery or after
switching-on without back- up battery. |
DATA_TYPE DECIMAL mode Source: T1st < 150 ms Tsc < 6 us Acceptor: Tac < 8 us Trd < 10 us DATA_TYPE BINARY mode Source: T1st < 150 ms Tsc < 6 us Acceptor: Tac < 3 us Trd < 6 us
Č | 0 | Г | - | Γ | 2 | ы | Γ | 4 | 2 | 9 | 7 | - | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
₽7 + | 0 | 0 | 0 | 0 | - | - | - | |||||||||||||||||
∔ ∔
8 2 |
0 | C | 0 | - | ~ |
|
~ | 0 | 0 | 0 | - | - | - | |||||||||||
≷> |
1 ISO-
7 bit |
dec
equiv |
ATN = 1 |
1SO-
7 bit |
dec
equiv |
ATN = 1 |
ISO-
7 bit |
dec / | ATN = 1 |
ISO-
7 bit |
dec / | ATN = 1 |
ISO-
7 bit |
dec | A
equiv |
VTN = 1 | tso- |
dec A
equiv |
= NT | ISO- | dec ATN = |
1 ISO-
7 bit |
dec | ATN = 1 | |
0 | 0 | NUL | 0 | DLE | 16 | SP | 32 | 0 | 0 | 4 8 | 16 | ₿ | 64 | 0 | ٩ | 80 | 16 | - | 96 | ď | 112 | |||
|- ] | 000 | SOH | - | GTL | DC1 | 17 | ГГО | 33 | - | 49 | 17 | ۲ | 65 | - | σ | 81 | 17 |
70 |
26 | σ | 113 | |||
∖∼ | 0 0 1 0 | ) STX | ~ | DC2 | 18 | 8 | ~ | 3 | 50 | 18 | 8 | 99 | 2 | œ | 82 | 18 | ٩ | 98 | 114 | |||||
\ ~ | 0 0 1 1 | ETX |
|
S | 19 | ¥ | 35 | ю | ю | 51 | 19 | υ | 67 | З | S | 83 | 19 | 66 | S | 115 | ||||
\◄_ | 0 1 0 0 | EOT | 4 | SDC | DC4 | 8 | DCL | ⇒ | 36 | 4 | 4 | 52 | 20 | ٥ | 68 | 4 | 84 | 20 | σ | 100 | 116 | |||
≜_ | 0101 | ENQ | 2 | РРС | NAK | 21 | РРО | % | 37 | 5 | 5 | 23 | 21 | ш | 69 | 5 | ⊃ | 85 | 21 | υ | 101 | 117 | ||
٨ | 0 1 1 0 | ACK | o | SΥN | 52 | ళ | æ | 9 | 9 | 54 | 22 | ц | 20 | 9 | > | 86 | 22 | 102 | > | 118 | ||||
0 1 | I BEL | ~ | ETB | 33 | • | 33 | 7 | 2 | 55 | 23 | ჟ | 71 | 7 | 3 | 87 | 23 | ອ | 103 | 3 | 119 | ||||
\ ∞ | 1 0 | BS | 8 | GET | CAN | 24 | SPE | 40 | ω | 8 | 56 | 24 | Т | 72 | 8 | × | 88 | 24 | ء | 104 | × | 120 | ||
ഽ | 1 0 0 1 | H | б | тст |
N
U U |
55 | SPD | ^ | 41 | 6 | თ | 57 | 25 | 73 | б | ≻ | 89 | 25 | 105 | ~ | 121 | |||
\°
⊳ |
1 0 1 ( | г | 10 | SUB | 56 | * | 42 | 10 | •• | 58 | 26 |
۔
|
74 | 10 | Ν | 6 | 26 | 106 | Z | 122 | ||||
\ = | 101 | 4 | 7 | ESC | 27 | + | 43 | ŧ | •• | 29 | 27 | ¥ | 75 | 1 | 91 | 27 | × | 107 | 123 | |||||
_5
[⊒] |
1 1 0 ( | 2 FF | 12 | FS | 58 | • | 44 | 12 | Y | 09 | 28 | 76 | 12 | ~ | 92 | 28 | - | 108 | 124 | |||||
\ | 1 1 0 | 1 CB | 13 | GS | 5 | 1 | 45 | 13 | 11 | 61 | 59 | Σ | 22 | 13 | _ | 93 | 29 | Ε | 109 | 125 | ||||
\₹_ | 0 80 | 14 | RS | 8 | • | 46 | 14 | ^ | 62 | 30 | z | 78 | 14 | ٢ | 94 | 30 | с | 110 | 1 | 126 | ||||
\₽ | 1 | 15 | SN | 31 | .~ | 47 | 15 | ¢. | 63 |
UNL
UNL |
0 | 62 | 15 | t | 95 | 0 | 111 | L 127 | ||||||
| |
AA
Ab |
]1 | } | 1 | ADDF | NUP SSS | } | 1 | }J |
ONDARY
DRESS ROUP |
} |
Figure 4.17 ISO-code table.
There are three ways to get the oscilloscope out of the remote situation and these are: hardware reset (power off, power on), and via an IEEE bus command GTL (Go To Local) or by activating the REN line. To get the oscilloscope out of its current remote situation send:
After executing this command the oscilloscope is listening again to the knobs at the frontpanel.
It is possible for the controller to tell the oscilloscope when to start a measurement by using the IEEE bus GET (Group Execute Trigger) command. This is done by sending:
Since there are two modes of measurement (recurrent, single) there are two different interpretations possible for the oscilloscope:
Recurrent : no interpretation, measurements are continuous Single : re-arm the single shot mode
For these modes there will be a service request after the measurement is ready. This service request will stay active until the status of the oscilloscope is loaded into the controller. After this, the service request is reset by the oscilloscope and can be enabled by a new GET (Group Execute Trigger) command.
The oscilloscope is capable of receiving and executing an SDC (Selective Device Clear) command from the IEEE bus. The controller sets the selected oscilloscope in the selective device clear state by sending:
Device listener address followed by:
X0000100 (with ATN true)
On receiving this command the oscilloscope will, execute the following:
The oscilloscope is capable of receiving and executing a DCL (Device Clear) command from the IEEE bus. The controller sets all the devices in the system in the device clear state by sending:
On receiving this command the oscilloscope will, execute the following:
The serial interface described in this section is primarily intended to interconnect measuring instruments with other instruments to form a measuring system. A number of disciplines are already laid down for serial interfaces, but these disciplines mainly relate to interchanges between data terminal equipment (DTE) and data communication equipment (DCE). For measuring systems, the serial interfaces referred to must be regarded as connecting data terminal equipment to another DTE. As a consequence, these former disciplines and procedures are not always valid for measuring systems and modifications may be necessary as outlined in this chapter.
Figure 5.1 Typical configuration in measuring systems.
The V24 interface is based on the CCITT-Standard V24,28 giving specified signal characteristics for connecting data terminal equipment (DTE) and data communication equipment (DCE). V24 gives the functional specification of the circuits, whereas V28 specifies the electrical compatibility. The standard ISO 2110 assigns connector pin numbers to the circuits. All these documents are covered by the American Standard EIA-RS232-C except for the interchange circuit identification. The mode of data transfer is digital, using the bit serial, byte serial method, over one signal line with common return.
For efficient data transfer, the following characteristics must be considered.
5-1
To enable correct detection of characteristics received, some synchronization between transmitter and receiver is necessary. This is achieved by adding framing information to the data (ISO 1177). For the oscilloscope asynchronous data transfer is used.
Asynchronous formatting is mostly used for measuring systems; common for low speed applications. It adds framing information bits to each data character. Framing information is one start bit preceeding a data character and one or two stop bits following it.
Interfaces operating at speeds up to 1200 baud normally use two stop bits; those operating above this speed normally use one stop bit. In the "standby" state, when no characters are ready to be transmitted the transmit line is held in the logical "1" state. In asynchronous transmission mode, the even parity is the default value.
Different character lengths are possible. In measuring systems, 7 or 8 bit lengths are typical and are often switch-selectable. The character length excludes parity, start and stop bits. Normally, the ISO 7-bit code (ASCII equivalent) is used, the 8th bit being used for the parity. The least significant bit (LSB) is sent first.
The speed of the data transmission is specified in bits/sec by the baud rate, which must be selected to apply both to the transmitter and the receiver. Baudrates in use are:
75, 110, 150, 300, 600, 1200, 2400, 4800, 9600 and 19200 baud (bits/sec).
A serial interface is said to operate in a simplex mode or a duplex mode depending on whether it can handle data transfer in one or both directions.
This interface handles data transfer in both directions; i.e. it can transmit and receive (Full Duplex mode).
TRANSMITTER | RECEIVER | |
---|---|---|
] ~[ |
MAT 2760 |
Full duplex means that:
The correct data transmission parameters can be set by performing following steps through the several menues starting in the main DISPLAY menu (see fig. 5.4).
Example: 1200 baud, 8 data bits, 1 stop bit, no parity.
ACTUAL MENU | STEP | PRESSING | KEY# | NEW MENU |
---|---|---|---|---|
DISPLAY | 1 | OPTION> | 8 | DIGDIAN ODTION 1 |
DISPLAY OPTION 1 | 2 | OPTIONNAME> | 1/5 | OPTION INTERFACE |
OPTION INTERFACE | 3 | RS232-C | OPTION RS232-C | |
OPTION RS232-C | 4 | FRAME | 1 | RS232-C FRAME |
RS232-C FRAME | 5 | 1 STOP BIT | 2 | RS232-C FRAME |
RS232-C FRAME | 6 | 8 DATA BIT | 4 | RS232-C FRAME |
RS232-C FRAME | 7 | NO | RS232-C FRAME | |
RS232-C EXECUTE | 8 | EXECUTE | 8 | OPTION RS232-C |
OPTION RS232-C | 9 | OUTP SPEED> | 2 | RS232-C OUTP SPEED |
RS232-C OUTP SPEED | 10 | UP/DOWN | 5/6 | RS232-C OUTP SPEED |
ĺ | UNTIL 1200 (1K2) | ROZOZ O COTT SFEED | ||
RS232-C OUTP SPEED | 11 | RETURN | 8 | OPTION RS232-C |
OPTION RS232-C | 12 | INP SPEED> | 3 | RS232-C INPUT SPEED |
RS232-C INPUT SPEED | 13 | UP/DOWN | 5/6 | RS232-C INPUT SPEED |
UNTIL 1200 (1K2) | 5/0 | NOZOZ O INTOI SPEED | ||
RS232-C INPUT SPEED | 14 | RETURN | 8 | OPTION RS232-C |
Parity are displayed
SDPISPOSP Output Speed Input Speed Parity Data bits Stop bits |
l now |
in the menu.
18N1 K21K2 1K2 (1200) 1k2 (1200) N 8 1 |
)) | blop bleb, and the |
T | ||||
OPTION RS232-C | 15 | RETURN | 8 | OPTION INTERFACE |
OPTION INTERFACE | 16 | RETURN | 8 | DISPLAY OPTION 1 |
DISPLAY OPTION 1 | 1/ | RETURN | 8 | DISPLAY |
Figure 5.4 Initial setting.
This section deals with a number of protocols that are not standarized in V24,28 documents, but are applied to instruments equipped with a serial interface.
The service request and serial poll protocol were originally developped and intended for IEC interfaces, but its application has been extended to serial interfaces. This section deals with the implementation of the protocol for serial interfaces in Philips test and measuring instruments.
Serial interfaces do not provide a dedicated service request interrupt line. This means that the facilities for service request in devices equipped with these interfaces are somewhat restricted.
If a not masked reason for service request exists, the RQS-bit in the status byte indicates that service is required; if the reason to request for service is masked, the RQS-bit is not set. In any case, the reason may be specified in other bits of the status byte. A controller operating with devices via serial interfaces can periodically poll the devices to check whether service is required or not. The controller executes a serial poll by sending the interface message ESC7 (1/B, 3/7) to a device. Upon receipt of such a poll command, the device will respond by transmitting the ASCII equivalent of the status byte.
If the oscilloscope status is LOCAL, an ESC7 should be terminated with an SPR. The oscilloscope will put the status word on the bus immediately after the receipt of the SPR.
If the oscilloscope status is REMOTE, an SPR is not necessary;, the status word will be put on the bus immediately after the receipt of ESC7.
Figure 5.5 Serial poll action.
This protocol was also originally intended for application with IEC interfaces; but extended to serial interfaces. This section deals with the implementation for serial interfaces for Philips test and measuring instruments. The following possibilities exist for devices equipped with a serial interface and provided with a remote local interface function.
A transfer from the local to the remote state can only be performed by a controller by sending the interface message ESC2 (1/B, 3/2). Upon receipt of this "Go to remote" message, an instrument will unconditionally go into the remote state.
A transfer from the remote to the local state can be performed either by the controller or by the device in the following ways:
After power on, the remote local function is always in the local state.
Instruments equipped with a serial interface and provided with a device clear function, execute this function on receipt of the interface message ESC4 (1/B, 3/4) i.e. device clear. The device clear function returns the device function to a predetermined state. Interface settings (e.g. block separator) and local/remote status are not affected.
Instruments equipped with a serial interface and provided with a device trigger function, execute this function on receipt of the interface message ESC8 (1/B, 3/8) i.e device trigger. The trigger starts a predetermined device action.
Pin
no. |
CCIT
V24 circuit |
RS232-C
eq. |
CCITT-V24 descr.
For DTE-DCE |
Cable
connection DTE DTE |
---|---|---|---|---|
1 | 101 | AA | Protective ground | ·( |
2 | 103 | BA | Transmitted data | ) |
3 | 104 | BB | Received data | ) |
4 | 105 | CA | Request to send | |
5 | 106 | СВ |
Ready for sending
(CTS clear to send) |
|
6 | 107 | СС |
Data set ready
(DSR) |
|
7 | 102 | АВ | Signal ground | > |
8 | ||||
9 | ||||
10 | ||||
11 | ||||
12 | ||||
13 | X | |||
14 | ||||
15 | ||||
16 | ||||
17 | ||||
18 | ||||
19 | ||||
20 | 108.2 | CD |
Data terminal
ready (DTR) |
|
21 | ||||
22 | ||||
23 | ||||
24 | ||||
25 |
Figure 5.6 Pin and circuit allocation.
5.6 DATA TRANSFER RATE CALCULATION (RS232-C):
Transfer-time calculation for decimal data transfer via the serial interface. Example: Transfer of 100 data points in decimal format from the oscilloscope to a controller. Interface set-up Baudrate : 1200 Data bits: 8 Stop bits: 2 Parity : NO Mnemonics (sent by the controller) REG Ø,MSC TRACE,INTF RS232_OUT.Ø,DATA_TYPE DECIMAL, BGN Ø,END 99,CNT 1,DAT ?
Response (from the oscilloscope after receipt of DAT ?)
DAT 100 S***[]S***[]S***[].....S***{}
Worst-case a trace data point has a decimal value of -512 (e.g.), this means that each datapoint transmitted consists of 5 bytes.
Calculation
The total number of transferred bytes is:
Each transferred byte looks like:
There are 11 bits per frame and a total transfer of 508 frames. This means a total transfer time for 100 data points of:
508 * 11 = 5588 bits => 5588/1200 = 4.65 s
In a formula:
Transfertime=(l+databits+stopbits+parity)(5*(number of data points)+9)
Transfer-time calculation for binary data transfer via the serial interface.
Example: Transfer of 100 data points in binary format from the oscilloscope to a controller.
Interface set-up | Baudrate : | 1200 | Data bits | 3: | 8 |
---|---|---|---|---|---|
Stop bits: | 2 | Parity | : | NO |
Mnemonics (sent by the controller)
REG Ø,MSC TRACE,INTF RS232_OUT.Ø,DATA_TYPE BINARY, BGN Ø,END 99,CNT 1,DAT ?
Response (from the oscilloscope after receipt of DAT ?)
DAT 100[]#B<Hn><Ln><Hb><Lb><Hb><Lb><}
Worst-case a trace data point has a decimal value of -512 (e.g.), this means that each data point transmitted consists of 2 bytes.
Calculation
The total number of transferred bytes is:
12 + 100 * 2 = 212 bytes Number of bytes per data point (always 2) Number of data points DAT 100[]#B<Hn><Ln> (total 12 bytes)
Each transferred byte looks like:
FRAME:
There are ll bits per frame and a total transfer of 212 frames. This means a total transfer time for 100 data points of:
212 * 11 = 2332 bits => 2332/1200 = 1.94 s
In a formula:
Transfertime=(l+databits+stopbits+parity)(2*(number of data points)+13)
baudrate
Bus driver requirements DATA (TXD, RXD) Spacing "0" > 3 V Marking "1" < -3 V CONTROL (RTS, CTS, DSR, DTR) ON > 3 V < -3 V OFF Current output < 10 mA Output (driver) Line voltage (Vo) of output -7 V < Vo < 7 V impedance 300 Ohm Input (terminator) Line voltage (Vi) of input -25 V < Vi < 25 V impedance 3000 < R1 < 7000 Ohm
For RS232-C interfaces a 25-pole connector is used.
Connector requirements:
Cable requirements:
The cable shall be as short as possible.The cable length may not exceed 15 meters.
However, where a longer cable is required, the total capacitance may not exceed 2500 pF.
- The cable will be a "null modem" cable. A null modem cable implies that the wire links between the pins needed to connect two DTEs are provided within the cable (e.g. pin 2 connected to pin 3 of the other terminal).
Figure 5.7 RS232-C connector.
The interface is capable to carry out the following actions:
SYSTEM FUNCTIONS:
Front handling (FRO Ø).
- Transfer of frontpanel settings from oscilloscope to controller. - Transfer of frontpanel settings from controller to oscilloscope.
Register handling (REG Ø, 1, 2 or 3)
- The oscilloscope can ask for service and will respond its status word when the controller executes a serial poll.
This section deals with the user friendly messages to sent to an oscilloscope or to receive from an oscilloscope via a controller. The basic purpose of the message structure is to provide a flexible tool for moving instructions and/or data into and out of the oscilloscope.
A message record consists of a sequence of one or more message units.
< HEADER > < | BODY > < HI | EADER > < BODY | >|< HE | ADER > | < BODY | >| |
---|---|---|---|---|---|
SP | USP | SP | USP | SP | SPR |
SRØ | SR1 | SRØ | SR1 | SRØ | SR3 |
First message | unit Seco | ond message uni | t Thir | d message unit |
NOTE: - Only the last message unit can be a query unit (?).
Figure 6.1 Message structure.
A message record is a sequence of one or more message blocks constituting the complete device-message. A message begins when a device starts sending data for the first time following a reset or a previously sent record separator; it ends with the record separator.
Separators are used to distinguish between the various parts in the message, and to mark the several hierarchical levels. In desceeding order of level they are denoted as SR3, SR2 and SR1, for respectively, the record-, block- and unit- separator.
Following separators are used:
TO SEPARATE A HEADER AND A BODY
IEEE: | RS232: | |
---|---|---|
Indicated as: | SRØ | SRØ |
Preferred: space | ||
Hexadecimal representation | 20 | 20 |
Decimal representation | 32 | 32 |
The unit separator is used within a block to distinguish between related message units. However, it is quite usual that the header of the next unit implies the unit separator.
IEEE: | RS232: | |
---|---|---|
Indicated as: | SR1 | SR1 |
Preferred: comma | , | , |
Hexadecimal representation | 2C | 2C |
Decimal presentation | 44 | 44 |
The block delimiter is used within a message to distinguish between message blocks. Also here it is common practice that the header of the next block implies the block separator if a message exclusively consists of blocks that only contain one message unit.
IEEE: | RS232: | |
---|---|---|
Indicated as: | SR2 | SR2 |
Preferred: linefeed | LF | LF |
Hexadecimal representation | ØА | ØА |
Decimal representation | 10 | 110 |
The record separator is used to terminate a message. It indicates that there is no additional information available. In IEEE interfaces the END message is sent (via the ATN and the EOI-lines), concurrent with the NL message on the data bus.
IEEE: | KSZ3Z : | |
---|---|---|
Indicated as: | SR3 | SR3 |
Preferred: linefeed + END | LF + END | LF |
Hexadecimal representation | ØA | ØA |
Decimal representation | 10 | 10 |
End activates the EOI interface management line.
HEADER indicating the type or quality of the data following in thebody. They refer in general to the quantity of the data rather then to units.
MAT2767
Figure 6.2 Header.
BODY containing the data to be transferred. It may represent different data types.
There are two types of bodies possible:
- a character data body - a numerical data body
CHARACTER DATA BODY
MAT 2768
Figure 6.3 Character data body.
There is no restriction for the length of the body, however it must be fixed per device function.
Numerical data can be represented in 3 different ways, depending upon the application:
Instruments that are able to implement a certain numerical representation (NR) are also able to implement a lower numbered NR.
6-4
Implicit decimal point notation (NR1):
(-32768 < NR1 < 32767)
Figure 6.4 Numerical data body - NRl notation.
Explicit decimal point notation (NR2):
Figure 6.5 Numerical data body - NR2 notation. The number zero can be noted as .Ø (and of course Ø, as NR1)
Scaled representation (NR3):
Figure 6.6 Numerical data body - NR3 notation.
Leading zero suppression (except for the exponent) is preferred for all numeric notations.
The body defines in this way the new state in which a function, defined by the previous header will end up.
Example:
Common
Notation |
NR1 |
Common
Notation |
NR2 |
Common
Notation |
NR3 |
---|---|---|---|---|---|
238 | +0238 | 32.4 | +32.4 | 5600 | +005.6E+03 |
-1 | -0001 | -3 | -003. | 0.02 | +020.0E-03 |
0 | +0000 | 0 | +000. | -4.2 | -004.2E+00 |
An oscilloscope can be set in the local or in the remote states:
Local state : The operator can control the oscilloscope manually, (REMOTE led off). In this state, the controller is able to switch the oscilloscope to "remote state". Remote state: Only the controller on the bus can control the oscilloscope. (REMOTE led on).
Figure 6.7 Two states of the osciloscope.
In the oscilloscope we can devide the REMOTE state into two different states:
Front handling state : Used for programming a new acquisition setting. Register handling state: Used for programming in stored settings and for data transfer. This function is typical for a digital storage oscilloscope.
The way to enter another state is to ask for that state. However, there are exceptions.