Applies To:
  • CitectSCADA 3.x 4.x

Question: What is the differences between a Citect Manager Node and a standard Citect Node?

The basic difference between the standard Citect client and a Manager node is that the manager node cannot be used for control. This allows the manager node to be used as a safe light weight Citect client. The manager node is designed to prevent control of the plant with the following features:

The manger node cannot be a Alarm/Trend/Report or I/O Server. This prevents direct access to any server data and if the manager node is shutdown it does not effect the rest of the plant. The manager node can be a client to any other Alarm/Trend/Report and I/O server for read only access. The manager node cannot write to any Physical I/O device. This includes DISK PLCs on the I/O server. You can write to MEMORY PLC's on the local manager node as this cannot effect control of the plant. The manager node can read from any I/O device and from any I/O Server.

The manager node cannot use the MsgRPC() function as this would allow remote access to control on a server. The manager node is prevented from any manipulation of alarms. This is prevented by not allowing use of the following functions: AlarmAck(), AlarmDisable(), AlarmEnable(), AlarmClear(), AlarmSetThreshold(), AlarmSetPriority(), AlarmComment(), AlarmSumSplit(), AlarmSumDelete(). The low level alarms functions are also not allowed as the manager node cannot be an alarm server and these functions are only available on an alarm server. These functions include AlarmAckRec(), AlarmDisableRec(), AlarmEnableRec(), AlarmClearRec(), AlarmFirstCatRec(), AlarmNextCatRec(), AlarmFirstTagRec(), AlarmNextTagRec().