User`s guide

Page 37

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

5.2. Standard Header Format (All Tables) … Words [0



The header is the first four (4) words in the data block.

Please refer to the list of tables in Figure 3-2.

5.2.1. Word [0]: Table ID

As in the first word in the block data transfers, this first word is the Table ID. This can also be

considered the “Command ID”.

5.2.2. Word [1]: Read / Write Command Indicator

(If a Read/Write Table):

If word [1] == 0 this is a command from the PLC to the 1746-C to read the specified table

from 1746-C memory and place it into the exchange buffer so the PLC can read it out

… words [0

 63].

If this is table [0], then this read back will include all current configuration information

(at the front of the table) and current system run-time information (at the back of the

table).

If word [1] =/= 0 (any non-zero value) … this is a command from the PLC to the 1746-C to

remove the supplied table of data from the exchange buffer and place it into the 1746-

C standard memory (tables).

- If this is table [0], then the configuration information is written.

- Otherwise, the table information is written to the 1746-C.

- If this is the type of table that actually writes data to the actuators, then that data

is outputted to the actuators.

(If a Read Only Table):

This word is ignored and the table is only read.

5.2.3. Word [2]: Reserved / Firmware ID

When received by the 1746-C from the PLC, this word is ignored (reserved for future use).

When transmitted from the 1746-C to the PLC, this word contains the firmware ID. This is a decimal

number representing the 1746-C firmware ID. For instance, if the value in table [0] … word [2] is 400,

the firmware version number is 4.00