Keithley 2750 Service Manual

3-8 Routine Maintenance Model 2750 Multimeter/Switch System Service Manual
Plug-in module relay closure count
The Model 2750 keeps an internal count of the number of times each module relay has
been closed. This count will help you determine if and when any relays require replace-
ment (see module contact life specifications). The count can be read or reset only via
remote as outlined below.
Closure count commands
Table 3-2 summarizes closure count commands.
Reading relay closure count
To determine the closure count of specific channels, send this query via remote:
:ROUTe:CLOSe:COUNt? (@clist)
Here, clist is the summary of channels. For example, to determine the closure count of
channels 1 and 4 of a module in slot 1, the following query would be sent:
:ROUT:CLOS:COUN? (@101,104)
The following query would determine the closure count of slot 1 module channels 1
through 10:
:ROUT:CLOS:COUN? (@101:110)
Tab le 3- 2
Closure count commands
Command Description
:ROUTe
:CLOSe
:COUNt? (@clist)
:INTerval < NRf>
:INTerval?
:RCOunt (@clist)
Route subsystem.
Path to CLOSe commands.
Query count for channels in clist (channel list).
Set count update interval in minutes (10 to 1440).
Query count update interval.
Reset count for channels in clist.*
* Unit must be in manufacturing calibration mode. See text below.

Keithley 2750 Specifications

General

Interface	GPIB, RS-232, Ethernet
Switching Speed	Up to 500 channels/second
Maximum Voltage	300V
Operating Temperature	0°C to 50°C
Measurement Functions	DCV, ACV, DCI, ACI, 2-wire Resistance, 4-wire Resistance, Frequency, Temperature
Resolution	6.5 digits
Current	1A
Maximum Current	1A