IDEC FC4A-C10R2 User Manual page 418

25: D L C
ATA INK OMMUNICATION
The communication sequence in the separate refresh mode is shown below:
Master Station
Slave 1 Comm.
Completion M8080
Master
Slave 2 Comm.
Station
Completion M8081
Slave 31 Comm.
Completion M8116
All Slave Comm.
Completion M8117
Slave
Slave Station 1
Station
1
Communication
Completion M8080
Slave
Slave Station 2
Station
2
Communication
Completion M8080
Slave
Slave Station 31
Station
31
Communication
Completion M8080
Refresh Time at Master Station for Communication with One Slave Station (Trf)
The master station requires the following time to refresh the transmit and receive data for communication with one slave
station.
[Baud Rate 19200 bps] Trf = 4.2 ms + 2.4 ms × (Transmit Words + Receive Words) + 1 scan time
[Baud Rate 38400 bps] Trf = 2.2 ms + 1.3 ms × (Transmit Words + Receive Words) + 1 scan time
Total Refresh Time at Master Station for Communication with All Slave Stations (Trfn)
The master station requires the following time to refresh the transmit and receive data for communication with all slave
stations, that is the total of refresh times.
[Baud Rate 19200 bps] Trfn = ∑ Trf = ∑ {4.2 ms + 2.4 ms × (Transmit Words + Receive Words) + 1 scan time}
[Baud Rate 38400 bps] Trfn = ∑ Trf = ∑ {2.2 ms + 1.3 ms × (Transmit Words + Receive Words) + 1 scan time}
Example: Refresh Time
When data link communication is performed with such parameters as transmit words 6, receive words 6, slave stations 8,
and average scan time 20 ms, then the total refresh time Trf8 for communication with all eight slave stations will be:
[Baud Rate 19200 bps] Trf8 = {4.2 ms + 2.4 ms × (6 + 6) + 20 ms} × 8 = 424.0 ms
[Baud Rate 38400 bps] Trf8 = {2.2 ms + 1.3 ms × (6 + 6) + 20 ms} × 8 = 302.4 ms
25-10
1 scan time
END Processed
Slave 1 Slave 2
Refresh Refresh
1 scan
END Processed
1 scan time
END Processed
1 scan time
END Processed
« FC4A M
ICRO
Slave 3
Refresh
S U ' M »
MART SER S ANUAL
Slave 31 Slave 1
Refresh Refresh