Measurement Computing CIO-RELAY08 - Manual (Page 14)

5.2 FORM C RELAYS (STANDARD VERSIONS)
Figure 5-5 is the schematic for a Form-C relay as used on the standard
CIO-RELAY08, -16, -24 and -32 boards.
The Form-C relay has a COMMON (COM), a normally open (NO), and a normally
closed (NC) contact. When a 0 is written to an output (OPn), the common and NC
are in contact. When a “1” is written to an output (OPn), the common and NO are in
contact.
Figure 5-5. Form C Relay
5.3 FORM A RELAYS (/M VERSIONS)
Figure 5-6 is the schematic for a Fo rm-A relay as used on mercury wetted (/M)
models.
A Form-A relay has COMMON (COM) and normally open (NO) con nections.
When a “0” is written to the output, the common and NO are disconnected. When a
“1” is written to the output (OPn), the common and NO are in contact.
Figure 5-6. Form A Relay
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