Panasonic FPS Series User Manual page 258

FPΣ User's Manual
Calculation example 4
Conditions: All stations have been added to an 8-unit link. Highest station number = 8. Relays
and registers have been evenly allocated. Scan time for each PLC: 5ms.
Ttx = 0.096
Pcm (per station) = 23 + (8 + 16) × 4 = 119
Tpc = Ttx × Pcm = 0.096 × 119 ≈ 11.43ms
Ts (per station) = 5 + 11.43ms = 16.43ms
Tlt = 0.096 × (13 + 2 × 8) = 2.79ms
Given the above conditions, the maximum value for the transmission time (T) of one cycle will be:
T max. = 16.43 × 8 + 2.79 + 5 = 139.23ms
Calculation example 5
Conditions: All stations have been added to a 2-unit link. Highest station number = 2. Relays
and registers have been evenly allocated. Scan time for each PLC: 5ms.
Ttx = 0.096
Pcm (per station) = 23 + (32 + 64) × 4 = 407
Tpc = Ttx × Pcm = 0.096 × 407 ≈ 39.072ms
Ts (per station) = 5 + 39.072 = 44.072ms
Tlt = 0.096 × (13 + 2 × 2) ≈ 1.632ms
Given the above conditions, the maximum value for the transmission time (T) of one cycle will be:
T max. = 44.072 × 2 + 1.632 + 5 = 94.776ms
Calculation example 6
Conditions: All stations have been added to a 2-unit link. Highest station number = 2. 32
relays and 2 register words have been evenly allocated. Scan time for each PLC: 1ms.
Ttx = 0.096
Pcm (per station) = 23 + (1 + 1) × 4 = 31
Tpc = Ttx × Pcm = 0.096 × 31 ≈ 2.976ms
Ts (per station) = 1 + 2.976 = 3.976ms
Tlt = 0.096 × (13 + 2 × 2) ≈ 1.632ms
Given the above conditions, the maximum value for the transmission time (T) of one cycle will be:
T max. = 3.976 × 2 + 1.632 + 1 = 10.584ms
NOTE
•
In the description, "stations that have been added" refers to stations which
are connected between station no. 1 and the highest station number and for
which the power supply has been turned on.
•
Comparing examples 2 and 3, the transmission cycle time is longer if there
is one station that has not been added to the link. As a result the PLC link
response time is longer.
•
The SYS1 instruction can be used to minimize the transmission cycle time
even if there are one or more stations that have not been added to the link.
8.7 PLC Link
241