Panasonic FP3 Technical Manual page 56

4-6. Communication Times
Maximum P/W PC Link Response Time "Maximum Rpc"
The maximum amount of time needed between an input transition from a Programmable Controller and the
corresponding output transition to the next Programmable Controller is calculated as follows ;
Maximum Rpc = TidA + TscA + T1 + Ttc + TscB + T2 + TscB + TodB
where :
TidA = Input delay time of the input transition at Programmable Controller "A".
TscA = Scan time at the Programmable Controller "A".
T1 = Time needed between the I/O update and the W Type(Wire) Link Unit's buffer update
= (1 +
Ttc = Time needed for one transmission cycle
TscB = Scan time at the Programmable Controller "B".
T2 = Time needed from the buffer update signal reception and the CPU memory update at
station "B".
= (1 +
where ;
Tsti max.=Time needed for PC Link processing by station "i".
TodB = Output delay time of the output transition from Programmable Controller station "B"
Station A
(UNIT NO. A)
Input transition
CPU scan
Buffer
Transmission
cycle
Station B
(UNIT NO. B)
Buffer
CPU scan
Output transition
52
Ttc
) x TscA
TscA
Ttc + Tsti max.
) x TscB
TscB
Here, the Tsti max. is supposed to be the longest time needed for
processing by one station.
Input delay I/O update
TidA
Approx. one scan time
I/O update
TscA
T1
Ttc
Buffer update
TscB
T2
Buffer update I/O update
TscB
TodB
Output delay