Omron C200HW-CLK21 Operation Manual page 294

Message Delay Times
RECV(98) Instruction
Maximum Delay Time
RECV(98) executed
Transmission processing
(command)
Transmission delay
Reception processing
(command)
Example
In this example, the maximum transmission delay is calculated for an instruc-
tion sending 256 words of data in a system with 32 nodes. Network specifics
are detailed below:
Baud rate:
Max. node number:
Number of nodes:
Number of polled nodes: 4
Number of words:
Data link:
Link Unit servicing (source node)
Transmission processing
Communications cycle time (See note.)
Transmission delay (command)
Reception processing
Link servicing interval (destination node)
Total (max. transmission delay)
Note This communications cycle time is calculated assuming that there is no node
that transmits event frames before the SEND command is issued.
The following indicates the data flow which will yield the maximum transfer
interval from the time the RECV(98) instruction is executed by the user pro-
gram to the time the Controller Link Unit stores the data in the local Unit's
memory area.
Note Be sure to take into account the time required for data links and program exe-
cution, which are not included in the following example.
Max. transmission delay
Max. transmission delay = Link Unit servicing interval (source node) + Trans-
mission processing (command) + Communications cycle + Transmission
delay (command) + Reception processing (command) + Link Unit servicing
2 Mbps
32
32
256
halted
Data stored
Reception processing
(response)
Transmission delay
Transmission processing
(response)
Section 8-4
PLC cycle time (source node)
0.00125 256 + 3 = 3.32
600 4 + 110 32 + 320
0 + 2,290 = 8,210 s 8.2 ms
0.008 256 + 0.112 = 2.16
2.2 ms
0.00125 256 + 2.3 = 2.62
2.6 ms
PLC cycle time (destination node)
PLC cycle time (source node)
2 + PLC cycle time (destination
node) + Peripheral servicing
time (destination node) +
16.3 ms
Link Unit servicing
(source node)
Communications cycle
Link Unit servicing (destination
node)
3.3 ms
0 + 4
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