Keithley 705 Instruction Manual page 21

3. Select appropriate line voltage and turn the Model 705's
on. Refer to paragraphs 2.2.1 and 2.3 respectively.
4. Press PRGM, 6, 2, ENTER. For complete details refer to
paragraph 2.6.7.
5. Program one Model 705 as the master by initiating front
panel Program 91. For complete details concerning the
front panel programs refer to paragraph 2.6.
6. Program remaining Model 705's as slaves by initiating front
panel Program, 92 for each of the remaining Model 705's.
To do this press PRGM button and then press 9, 2.
All remaining Model 705's will have to be programmed in
the same way. For complete details concerning the front
panel programs refer to paragraph 2.6.
NOTE
Initiating front panel Program 92 locks up the
Model 705 front panel except for program 90 and
91 which allow you to go to stand alone or
master. The following message is displayed while
the front panel is locked up.
I i;Lf?UE I
I
I
7. Press 0, 1, FIRST. (Programs channel 1 as the first chan-
nel.)
8. Press 6, 0, LAST. (Programs channel 60 as the last chan-
nel.)
NOTE
If the Model 705's are not daisy chained together,
pressing 6, 0 in step 8 causes the Model 705 to
display the following message for approximately
0.5 seconds.
-1
The display message indicates that there is no
channel 60.
9. Press INTERVAL, 0, 0, 2, 0, 0, 0, ENTER. (Programs the
interval time for two seconds.)
10. Press CHANNEL, RESET. (Turns on the channel LED,
selects the channel mode for display and resets the Model
705 to the programmed first channel.)
11. Press CONTINUOUS. (Selects the continuous scan mode
and turns on the continuous LED.)
12. Press the START/STOP button to initiate the continuous
scan mode.
Upon the actuation of the START/STOP button in step 12,
the continuous scan sequence starts from the programmed
first channel. The continuous scan mode operates in the same
way as in Example 3. That is, the first channel is closed for the
programmed interval time and the START/STOP LED is turn-
ed on; then the channel is opened, and the Model 705 ad-
vances to the next channel. This sequence is repeated up to
the last channel and then instead of advancing to the next
channel the Model 705 resets to the programmed first channel
and the entire sequence is repeated.
The scanning sequence can be stopped at any programmed
channel by simply pressing the START/STOP button. Press-
ing the START/STOP button during a continuous scan stops
the scan at the presently displayed channel, the channel re-
mains closed, and turns off the START/STOP LED. To start
the scanning sequence from the presently displayed channel,
press the START/STOP button. The START/STOP LED
turns on when resuming the scan,
To stop the scanning sequence, and reset the Model 705 to
the programmed first channel,simply press the RESET button.
Example 5 Temperature Scan-With the Model 7057 ther-
mocouple plug in card, the Model 705 can scan separate temp-
erature points. The Model 7057 thermocouple scanner card is
field installable in the Model 705 Scanner mainframe. Since the
Model 7057 combines the functions of a thermocouple scan-
ner and uniform temperature reference it is especially useful for
scanning thermocouples. The input terminals are #lO alloy-
copper set in an isothermal block to minimize temperature dif-
ferences. A thermistor sensor within the isothermal block is
used with a bridge network located on the Model 7057 to give
an indication of the temperature reference or cold junction.
The temperature of the heat sink is used to calculate the cor-
rected thermocouple output. The output voltages of each ther-
mocouple must be converted to temperature (OC or OF) using
appropriate thermocouple tables or polynomial equations. In-
put and output connections are made through the rear panel of
the Model 705 Scanner mainframe using #4 screw terminals on
the Model 7057. For complete details concerning the Model
7057 thermocouple scanner card refer to the Model 7057 In-
struction Manual.
In this example, the Model 705 will be programmed to scan
five separate temperatures. Also, the following parameters will
be programmed into the Model 705.
I. First channel is 1.
2. Last channel is 6.
3. Number of poles is 2.
4. Interval time is three seconds,
5. Use the continuous scan mode.
Use the following procedure to program the Model 705 for this
example:
1. If Example 4 is still set up, disconnect it. Connect the five
temperature sources to the Model 7057 via the #4 screw
terminals at the rear of the card.
2. Install the Model 7057 into the Model 705 Scanner main-
frame. Refer to paragraph 2.2.2 for scanner card installa-
tion instructions.
3. Select appropriate line voltage and turn on the Model 705.
Refer to paragraphs 2.2.1 and 2.3 respectively.
4. Press PRGM, 6, 2, ENTER. For complete details concern-
ing front panel programs refer to paragraph 2.6.
5. Press 0, 1, FIRST. (Programs channel 1 as the first chan-
nel.) Channel 1 is used to monitor the temperature of the
input terminals with the thermistor bridge.
6. Press 0, 6, LAST, (Programs channel 6 as the last
channel.)
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