Message Delay Times

Section 8-4

interval (destination node) + Transmission processing (response) + Communi- cations cycle + Transmission delay (response) + Reception processing (response) + Link Unit servicing interval (source node).

Link Servicing Interval (Source and Destination Nodes)

Link service processing is the same as the PLC’s peripheral servicing and is approximately 1 ms for Controller Link Units.

Transmission Processing

Commands: 2 ms

Responses: Number of words transferred 0.00125 ms + 3 ms

Communications Cycle Time (with Data Links Inactive)

See 8-2 Communications Cycle Time (on page 251).

Transmission Delay Time

Transmission delay time varies with the baud rate.

Baud rate

Transmission delay time

 

 

 

2 Mbps

Number of words transferred

0.008 + 0.112 ms

 

 

 

1 Mbps

Number of words transferred

0.016 + 0.224 ms

 

 

 

500 Kbps

Number of words transferred

0.032 + 0.448 ms

 

 

 

Note Commands: Transmission delay time is calculated assuming that the number of words to be transferred is zero.

Responses: Transmission delay time is calculated according to the number of words to be transferred.

Reception Processing

Commands: 2.3 ms

Responses: Number of words transferred 0.00125 ms + 2.3 ms

The I/O response time might increase due to noise or restrictions on the num- ber of frames that can be transmitted while the data link is operating.

Example

In this example, the maximum transmission delay is calculated for an instruc- tion receiving 256 words of data in a system with 32 nodes. Network specifics are detailed below:

Baud rate:

2 Mbps

Max. node number:

32

Number of nodes:

32

Number of polled nodes:

4

Number of words:

256

Data links:

Halted

272

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Omron CS1W-RPT01, CVM1-CLK21, CJ1W-CLK21-V1, C200HW-CLK21, CQM1H-CLK21, CS1W-CLK21-V1 operation manual 272