User manual

19 PCI-1762 User Manual
Chapter 3 Signal Connections
3.3 Relay Connections
After power on, the initial relay output status of PCI-1762 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", NC0, to position "NORMALLY OPEN", NO0.
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.