Plc Link Response Time; Response Time Of 1 Transmission Cycle - Panasonic FP7 User Manual

4.4 PLC Link Response Time

4.4.1 Response Time of 1 Transmission Cycle

The maximum value for the transmission time (T) of one cycle can be calculated using the
following formula.
 Calculation formula
(1) Ts (transmission time per station)
Calculation
Ts = Scan time + Tpc (PLC link sending time)
formula
Tpc = Ttx (sending time per byte) x Pcm (PLC link sending byte size)
Ttx = 1 / (transmission speed kbps × 1000) × 11ms ... Approx. 0.096 ms at 115.2 kbps
Pcm = 23 + (number of relay words + number of register words) x 4 (4 times based on ASCII
code)
(2) Tlt (link table sending time)
Calculation
Tlt = Ttx (sending time per byte) x Ltm (link table sending size)
formula
Ttx = 1 / (transmission speed kbps × 1000) × 11 ms ... Approx. 0.096 ms at 115.2 kbps
Ltm = 13 + 2 × n (n = No. of added stations)
(3) Tso (Master station scan time)
This should be confirmed using the programming tool.
(4) Tlk (link addition processing time)
When there is no station that is yet to be added to the link, Tlk = 0
Calculation
Tlk = Tlc (link addition command sending time) + Twt (addition waiting time)
formula
+ Tls (sending time for command to stop transmission if link error occurs) + Tso (master station
scan time)
Tlc = 10 x Ttx (sending time per byte)
Ttx = 1 / (transmission speed kbps × 1000) × 11ms ... Approx. 0.096 ms at 115.2 kbps
Twt = Default value: 400 ms
Tls = 7 x Ttx (sending time per byte)
Ttx = 1 / (transmission speed kbps × 1000) × 11ms ... Approx. 0.096 ms at 115.2 kbps
Tso = Master station scan time
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4.4 PLC Link Response Time
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