Appendix
C. I/O Connections
A 25 pin D-sub connector, located on the rear of the SQC-122c, provides Input/Output
connections. Refer to Section 3.6 for relay and input functional assignments.
Inputs can be activated either by connecting to a switch and shorting to Ground, or they
can be driven by a TTL compatible signal.
WARNING: These are not isolated inputs! The voltage level applied must be limited to
between 0 and +5 volts with respect to Ground.
WARNING: Output relays are rated for 30Vrms or 30VDC, at 2A maximum. Proper
fusing, and adequate wiring insulation and separation, should be provided to assure
these limits are not exceeded.
The pin assignments for the rear panel mounted I/O connector are shown below:
113
14 25
I/O Connector Wiring
Relay Pins Input Pins
Relay 1 14,15 Input 1 16
Relay 2 1,2 Input 2 17
Relay 3 3,4 Input 3 18
Relay 4 5,6 Input 4 19
Relay 5 7,8 Input 5 20
Relay 6 9,10 Input 6 21
Relay 7 11,12 Input 7 22
Relay 8 13,25 Input 8 23
Ground 24