Program Operation; Troubleshooting - Lakeshore 340 User Manual

9.1.4.5

Program Operation

Once either example program is running, try the following commands and observe the response of the
instrument. Input from the user is shown in bold and terminators are added by the program. The word [term]
indicates the required terminators included with the response.
ENTER COMMAND? *IDN?
RESPONSE: LSCI,MODEL340,123456,02032001[term]
ENTER COMMAND? KRDG? A
+077.350E+0
ENTER COMMAND? HTR?
+050.0%
ENTER COMMAND? CMODE 1,1
ENTER COMMAND? PID? 1
0020.0, 0010.0, 0005.0
ENTER COMMAND? PID 1,25,15,6
ENTER COMMAND? BEEP 1;BEEP?
1
ENTER COMMAND?
The following are additional notes on using either IEEE-488 Interface program.
• If you enter a correctly spelled query without a "?," nothing will be returned. Incorrectly spelled commands
and queries are ignored. Commands and queries should have a space separating the command and
associated parameters.
• Leading zeros and zeros following a decimal point are not needed in a command string, but are sent in
response to a query. A leading "+" is not required but a leading "–" is required.
9.1.5

Troubleshooting

New Installation
1. Check instrument address.
2. Always send terminators.
3. Send entire message string at one time including terminators.
4. Send only one simple command at a time until communication is established.
5. Be sure to spell commands correctly and use proper syntax.
6. Attempt both 'Talk' and 'Listen' functions. If one works but not the other, the hardware connection is
working, so look at syntax, terminators, and command format.
7. If only one message is received after resetting the interface, check the "repeat addressing" setting. It
should be enabled.
Old Installation No Longer Working
8. Power instrument off then on again to see if it is a soft failure.
9. Power computer off then on again to see if the IEEE card is locked up.
10. Verify that the address has not been changed on the instrument during a memory reset.
11. Check all cable connections.
Intermittent Lockups
12. Check cable connections and length.
13. Increase delay between all commands to 50 ms to make sure instrument is not being over loaded.
9-12
Lake Shore Model 340 Temperature Controller User's Manual
Identification query. Instrument will return a string identifying itself.
Query Kelvin Reading for Input A. Controller returns temperature
reading in kelvin.
Query Heater Output. Controller returns heater output in percent.
Set Control Loop 1 to Manual PID.
Query Current PID Status. Controller returns separate PID
settings.
Set Loop 1 PID values to 25, 15, and 6.
Combination command of setting the system beeper on and then
requesting the system beeper status.
Remote Operation