ADLINK ND-6054 - Manual (Page 43)

Introduction • 35
1.8.4 Using Relay Output
The ND-6060 contains two types of relay : Form C and Form A. The relay R3
and R4 are form C relays, and R1 and R2 are plain form A type. The
difference between these two types of relay are:
1. Form C Relay : ( R3, R4)
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 : ( R1, R2)
NO
COM
Control Bit = High (1)
NO
COM
Control Bit = Low (0)
Form A relay only has two contacts : NO (Normal Open) and
COM( Common). The COM post can make contact either NO post or not
contact NO 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 NO post does
not make contact. In normal power-up and reset, the relay is in low status.