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YASKAWA ELECTRIC
TOEP C710656 07A YASKAWA Power Regenerative Converter - D1000 Instruction Manual
C.6 Communications Timing
C.6 Communications Timing
To prevent a communications overrun in the slave converter, the master should wait a certain time between sending
messages to the same converter. In the same way, the slave converter must wait before sending response messages to
prevent an overrun in the master. This section explains the message timing.
◆
Command Messages from Master to Converter
The master must wait for a specified time between receiving a response and resending the same type of command to the
same slave converter to prevent overrun and data loss. The minimum wait time depends on the command as shown in
Table C.3 Minimum Wait Time for Sending Messages
Figure C.7
Figure C.7 Minimum Wait Time for Sending Messages
Set a timer in the master to check how long it takes for the slave converter(s) to respond to the master. If no response is
received within a certain amount of time, the master should try resending the message.
◆
Response Messages from Converter to Master
If the slave converter receives a command from the master, it will process the data received and wait for the time set in
H5-06 until it responds. Increase H5-06 if the converter response causes overrun in the master.
Figure C.8
Figure C.8 Minimum Response Wait Time
Command Type
Example
Minimum Wait Time
1
<1> If the converter receives command type 1 data during the minimum wait time, it will perform the command and then respond. However, if it
receives a command type 2 or 3 during that time, either a communication error will result or the command will be ignored.
• Control command (Run, Stop)
• Set inputs/outputs
• Read monitors and parameter values
2
Write parameters
H5-11 = 0: 50 ms
H5-11 = 1: 200 ms
3
Save changes using an Enter command
200 ms to 2 s, depending on the number
of parameters that were changed
24 bit length
Converter
Converter
Converter
Command message
Response message
Command message
Time
Master Send
Wait Time
PLC
→
PLC
→
→
PLC
D1000
Command message
Response message
Command message
PLC
→
Converter
PLC
→
Converter
Converter
→
PLC
24 bit length
H5-06
setting
Time
D1000