Normally Closed
Contacts 1. Hardware Connections
2. Equipment Setup
• Set DMM to: 4-wire ohms, autorange.
• Send *RST to the switch.
• Send CLOS (@100:115) to the switch to open all NC contacts.
3. Closed-Channel Reading (channel 00)
• Send OPEN (@100) to the switch to close channel 00.
• Trigger the DMM and record the reading.
4. Open-Channel Reading (channel 00)
• Send CLOS (@100) to the switch to open channel 00.
• Trigger the DMM and verify that an open circuit is indicated
(>10
8
Ω).
5. Closed- and Open-Channel Readings (channels 01-15)
• Repeat steps 3 and 4 for channels 01 through 15. Use
CLOS (@ccnn) and OPEN (@ccnn), where
cc = switch card number (01-99, leading zero not necessary)
nn = channel number (00-15)
Figure 2-3. Closed-Channel Resistance (NC Channels)
24 Verification Tests Chapter 2
