User`s manual

34
FX3U Series Programmable Controllers
User’s Manual - MODBUS Serial Communication Edition
6 Related Devices and Communication Status
6.1 Special Data Registers
D8410 D8430
Turn Around
Delay
M
The turnaround delay defines the minimum delay time that the
master has to wait after the transmission of a broadcast
message before transmitting the next request.
This delay allows the slaves to process the broadcast message
and prepare the reception of the next request.
Valid values: 0 to 32767 [ms]
0 will set the timeout to 400 ms
Note 1:This value can also be changed before each command
execution.
Note 2:If a value less than 3.5 character times (end of
message detection time) is selected, the master will
wait for at least 3.5 character times.
Note 3:The Turn Around delay and Message to Message delay
must be set for the slowest slave in the network.
R,W
D8411 D8431
Message to
Message delay
M, S
This value defines the minimum waiting time between two
messages. This time is used to detect the end of a message.
Valid values: 0 to 16382 (ms)
0 will be interpreted as 3.5 character times according to the
selected baud rate.
If a value less than 3.5 character times is selected, the master
will at least wait 3.5 character times.
Note 1:This value should be fixed during processing.
Note 2:This value can also be changed before each command
execution when setting up the network.
Note 3:The Turn Around delay and Message to Message delay
must be set for the slowest slave in the network.
R,W
D8412 D8432
Number Of
Retries
M
In the situation where a slave does not respond within the set
time by the Slave Response Timeout the master will try to
retransmit the message a set number of retries before it
terminates the command processing with a timeout error.
Valid values: 0 to 20 [times]
If a value of 20 or more is set the number of retries used by the
master is set to 20.
R,W
*1
D8413 D8433 Not used - - -
D8414 D8434
Slave Node
Address
S
Slave node address
Valid range: 1 to 247
Note: If during the initialization a value outside the valid range
is detected, the configuration is invalid and the slave will
not respond to any requests.
R,W
*1
Special Data
Register
Name Valid Detailed description R / W
CH1 CH2