PI Interface for Bailey Infi90 27Setpoint Read N90 point type 2 This is the setpoint of a control station block. See point type 1.
Control Output Read N90 point type 3 This is the control output of a control station block. See point type 1.
Ratio Index Read N90 point type 4 This is the ratio index of a ratio control station block. See point type 1.
Analog Read N90 point type 5 This refers to an analog output block (function code 30) in the plant loop.
Station Status N90 point type 6 Define a station status as a digital point in the PI Server. The status is returned as a 5 byte code from the CIU. The first byte is the process variable status and the last 3 bytes are zero. The second byte contains the station mode. This station mode is converted to a digital value of 0-5 for processing by the interface. The correlation between the mode byte and the PI digital value is if bit 7 is set then value = 5 (bypassed) else if bit 6 set then value = 4 (manual lock) else if bit 4 set then value = 3 (dig station failure) else if bit 1 set then value = 2 (cascade/ratio) else if bit 0 set then value = 1 (auto) else then value = 0 (manual) In addition, there are two more modes for the station status
auto lock and cascade lock, corresponding to states 6 and 7. This addition is necessary for some sites because the lock bit and the auto bit are not mutually exclusive. Set the PI digital point's digital state set to a digital state set that contains the following states
Value Station Mode 0 Manual
1 Auto
2
Cascade/Ratio
3
Dig Station Failure 4 Manual Lock
5
Bypassed 6 Auto Lock
7
Cascade Lock Share with your friends: