User`s guide

Page 77

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

320A/B DISCRETE OUTPUTS (COILS)

On a the other system types (320A and 320B), there are 3 outputs and they are addressed as coils [3-

5] in register [00] such that …

• Coil [3] … ESD / monitor relay.

• Coil [4] … User Output Relay #1

• Coil [5] … User Output Relay #2

Ordering is such that

• Coil [3] is the “bit-3” position … the 4

position in from the right.

• Coil [4] is the “bit-4” position … the 5

position in from the right.

• Coil [5] is the “bit-5” position … the 6

position in from the right.

FORMAT

There are 2 distinct areas in each word in table [16] …

• Command / Control bits … bits [15-13] in the upper most nibble.

• Desired coil (output) states …

o Bits [11 – 0] for TEC2000 systems

o Bits [5-3] in other systems.

Only these bits are set in this table. All others are zeroed out.

COMMAND / CONTROL

There are only 3 valid control values (upper nibble in the word) the PLC can send to the 1746-C

concerning this operation …

1000 (binary): Setting the upper nibble = 1000 … (top 1 bit set) tells the 1746-C to start

monitoring the status of the output coils and recording them in table [17]. The 1746-C will also

clear the desired state bits … set table [16] – bits [3-5] = 000.

1110 (binary): Setting the upper nibble = 1110 … (top 3 bits set) tells the 1746-C to

• Start monitoring the status of the output coils and recording their states in table [17].

• ONE TIME … write the desired states of the output coils to the particular actuator.

Once successful, bit [13] is set = 0 to prevent further (excess) writes.

3. 0xxx (binary): Setting the bit = 0 … (bit [15] = 0 and don’t care about the others) tells

the 1746-C to terminate monitoring and writing. Essentially, clear the command. The 1746-C

will also clear the bits representing the desired state of all output coils in table [16].

The 1746-C will only react to these values from the PLC in the upper nibble. All others are ignored.