APPENDICES
Appendix 3 Processing Time
App - 9
9
PROGRAMMING
10
DEDICATED
INSTRUCTIONS
11
TROUBLESHOOTING
APPENDICES
INDEX
(b) Performance of dedicated instructions (MBRW/MBREQ instruction)
1) Dedicated instruction processing time [unit: ms]
The dedicated instruction processing time is the time from the start of a
dedicated instruction until the completion device turns on.
Trc = Km + Ta + St + (Ttq + Ts + Ttr + Ti 3 + Gt or St, whichever is greater)
2) Calculation items
* 1 Request message transmission time [ms]:
Ttq = Request message size [bytes] Bits of 1 character / Transmission speed [bps] 1000
* 2 Response message transmission time [ms]:
Ttr = Response message size [bytes] Bits of 1 character / Transmission speed [bps] 1000
* 3 1 character time = Bits of 1 character / Transmission speed [bps] 1000
TableApp.9 Calculation items for the dedicated instruction processing time
Item Description Unit
Trc Dedicated instruction processing time ms
St Local station scan time ms
Km 9 (Constant) -
Ta
Message conversion time
RTU mode : 0
ASCII mode: 1 to 2
ms
Ttq
Request message transmission time
*1
ms
Ts Message processing time of target slave device ms
Ttr
Response message transmission time
*2
ms
Ti
Message interval
RTU mode :
When the transmission speed is 19200 bps or
less, "1 character time
*3
3.5"
When the transmission speed exceeds 19200
bps, "1.75ms"
ASCII mode: 0
ms
Gt
Data transmission delay time
RS-232 : 0 ms
RS-422/485: 1 character time
*3
2
ms