The GX6325 consists of three switching groups: A, B and C. Each group has 25 individual relays. The group relays A, B and C are connected to J6, J7 and J8 connectors as shown in the figure below.
GX6325 Architecture
The GX6325 has 75 Form 1C (SPDT) relays (see the figure below).
A typical GX6325 relay
The relays can be configured by software commands as closed (CO to NC) or as open (CO to NO)
When the relay is activated, the Change Over (CO) terminal is connected to the Normally Open (NO) terminal. When the relay is deactivated, the CO terminal is disconnected from the Normally Open (NO) terminal and connected to the Normally Close (NC). After the board is reset, all relays are deactivated. All of the CO, NO and NC terminals are connected to the connector (see J6 - Group A Relays Connector, J7 - Group B Relays Connector, J8 - Group C Relays Connector for J6, J7 and J8 connectors pins).