User`s guide

Page 89

Controlinc 1746-C (Version 5.21) Network Master Users Guide (2004-11-18)

6.1.3. Loading Table [0] with Configuration Information

To maximize system performance, the RLL must load configuration information that includes:

• The Number of Actuators on the network

• The Scan Period (number of network scans before a diagnostic scan).

• Whether or not to poll actuator totalizers.

• The number of additional valves to scan in the scan time-slice (before servicing the PLC).

• Table [13] … Which 320A actuators have Solid State Contactors for modulating control

• Any additional response delay for messages returning from actuators.

• Any specific register to poll from all nodes on the network.

• Any block of registers to get from a specified actuator (node) on the network.

• The value to reset the scan period counter.

• Any direct monitoring and control of discrete outputs on specific actuators on the network …

- coils [1000 – 1011] on TEC2000 systems.

- coils [3-5] on the other systems.

• Whether or not to poll input registers on TEC2000 systems.

The RLL is responsible for all configuration each time the system is reset. Except for 2 circumstances,

all configuration is performed in table [0]. Exceptions:

1. The RLL must identify which 320A actuators require SSR control and load table [13] with the

data. The optional “Solid State Relay” (SSR) is required to be in an actuator if the actuator is

to receive modulating control commands from any controller. If an actuator is supposed to

have an SSR installed, the network master will check, and if necessary, set the actuator internal

configuration bit (indicating an SSR is installed) before sending it a modulation command.

2. The RLL must identify which actuators (if any) the network master will poll and control the

discrete outputs on the actuator. This configuration information is loaded into table [16].

Upon reset, the 1746-C default configuration will assume:

• That there are 60 actuators on the network

• A Scan Period of 50 scans before a diagnostic scan.

• Do not poll the actuator totalizers.

• 2 additional valves to scan (making a total of 3 valves scanned) in the scan time-slice before

servicing the PLC.

• No 320A solid-state relays contactors installed in any actuators.

• No additional response delay for messages returning from actuators.

• No specific register to poll from all nodes on the network.

• No block of registers to get from a specified actuator (node) on the network.

• The scan period reset value is zero but do not reset the counter now.

• No direct monitoring or control of discrete outputs on specific actuators on the network.

• Do not poll TEC2000 input registers.