FPΣ User's Manual 
 
8.7 PLC Link 
239 
LD Body 
 
 
NOTE
 
If you are using FPWIN Pro Ver. 4.1 or higher and wish to use the addresses LD 
or LE, please enter "L0D" or "L0E". The compiler misinterprets LD and LE as a 
Load (LD) or Less Than or Equal To (LE) instruction and issues an error 
message. 
8.7.7  PLC Link Response Time 
The maximum value for the transmission time (T) of one cycle can be calculated using the 
following formula. 
T max. = Ts1 + Ts2 +                    + Tsn + Tlt + Tso + Tlk
 
1
 Ts (transmission time per station) 
Ts = scan time + Tpc 
  Tpc = Ttx × Pcm 
  Ttx = 1/transmission speed × 1000 × 11ms ≈ 0.096ms at 115200bit/s 
  Pcm = 23 + (number of relay words + number of register words) × 4 
Tpc (PLC link sending time) 
Ttx (sending time per byte) 
Pcm (PLC link sending size) 
2
 Tlt (link table sending time) 
Tlt = Ttx × Ltm 
  Ttx = 1/transmission speed × 1000 × 11ms ≈ 0.096ms at 115200bit/s 
  Ltm = 13 + 2 × n 
Ttx (sending time per byte) 
Ltm (link table sending size) 
n = number of stations being added 
3
 Tso (master station scan time) 
The master station scan time should be confirmed using the programming tool. 
4
 Tlk (link addition processing time) 
If no stations are being added, Tlk = 0. 
Tlk = Tlc + Twt + Tls+ Tso