ADLINK Technology cPCI-7252 - Chapter 4 Operation Theorem; Using Relay Output

18 •• Operation Theorem
4
Operation Theorem
4.1 Using Relay Output
The PCI-7250 contains two types of relay : Form C and Form A. The
relay R0 ~ R3 are form C relays, and R4 ~ R7 are plain form A type.
Note that the cPCI-7252 contains Form C relay only. The difference
between these two types of relay are :
1. Form C Relay : (R0 ~ R3)
NO
NC
COM
Control Bit = High (1)
NO
NC
COM
Control Bit = Low (0)
Form C relay has three contacts : NC (Normal Close), NO (Normal
Open), and COM (Common). The CM post, located at the middle, can
make contact either NO post or NC post. When the control bit is high
(1), the COM post and NO post are contacted. If the control bit is low
(0), the COM post and NC post make contact.
In normal power-up and reset, the relay is in low status.
2. Form A Relay : (R4 ~ R7)