User Manual

2400 Series SourceMeter
®
User’s Manual Contact Check Function F-5
A contact check pass condition occurs when the resistance of the device-under-
test connection paths are less than the selected threshold resistance value.
Contact check failure indications
There are several options to handle failure conditions detected by contact check:
• Via trigger system
• The front panel display shows “OPEN LEAD.”
• User-defined bits can be set on the Digital I/O port for LIMIT 4 (one of the
hardware limits in the Digital I/O control scheme) as controlled from the
front panel or with :CALCulate2:LIMit4 commands. (See
“Front panel con-
tact check operation,” page F-11, and “Remote contact check operation,”
page F-14.)
• Bit 18 of the 24-Bit Status word is set if there is an open lead and can be
read over the GPIB or RS-232 port, if LIMIT 4 is enabled. Pass/Fail status
for that limit is also contained in the status word. (See
“FORMat sub-
system,” page 18-47.)
• Bit 10 of the Measurement Condition and Measurement Event Registers
are set if a contact check failure occurs. You can use a Service Request
(SRQ) to query the state of these bits. (See
“Measurement Event Register,”
page 15-13 and Figure 15-6.)
Auto and manual ohms
Contact check can be used with either the auto or manual ohms modes. See
“Ohms measurement procedure,” page 4-4 for more information.
Table F-1
Recommended contact resistance threshold values
Nominal DUT
Resistance Threshold
2Ω
20Ω
200Ω or higher
2Ω
2Ω or 15Ω
2Ω, 15Ω, or 50Ω