Chapter 3 Signal Connections
PCI-1761 User’s Manual
22
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3.3 Relay connections
After power on, the initial relay output status of PCI-1761 is shown as
below:
Figure 3-2: Relay output connection
A write operation to I/O address, BASE +0, will change the output
status of each relay. For example, if Bit 0 of BASE +0 is set "1" (logic
high), relay 0, K0, will switch from position "NORMALLY CLOSED",
R0_NC, to position "NORMALLY OPEN", R0_NO. This means that
LOAD2 will be de-energized, while LOAD1 is energized.
To summarize, the "COMMON" line connect to the "NORMALLY
CLOSED" line, if the corresponding bit is set as 0 (power-on initial
status). Otherwise, if the corresponding bit is set as 1, then the
"COMMON" line will connect to the "NORMALLY OPEN" line..
