User`s guide

Page 64

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

5.4.8. Tables [9 & 10]: Digital Input Accumulators (Totalizers) #1 & 2

Words [4  63] PLC access: Read / Write

These tables contain 16-bit accumulator (totalizer) numbers stored in holding registers [66 & 67] in the

actuators. This data is retrieved with a separate Modbus read command when the particular actuator

is being polled (scanned).

• Table [9]: Value for Accumulator (Totalizer) #1

• Table [10]: Value for Accumulator (Totalizer) #2

These tables are not polled for unless the 1746-C is configured to allow it …

• if Table [0] – Word [7] == 0: The accumulator/totalizer information is NOT requested when

actuators are polled (

the default).

• if Table [0] – Word [7] =/= 0: The accumulator/totalizer information is requested when

actuators are polled.

The PLC may reset these tables (and the counters in the actuators) with any value is prefers. All it

needs to do is insert the new value in the table and send it to the 1746-C as a write command. The

1746-C will then send the value to the actuator.

A read back of Tables [9 & 10] will

• If a write command issued: reflect the write command accepted by the 1746-C

• If a read command issued: reflect the last known values of the totalizer registers in the

actuators.