Toshiba TOSVERT VF-S15 Instruction Manual page 5

 Relay sequence function
In case that an inverter is controled by a PLC (programmable logic controller), the PLC receives,
processes, and sends the signals as processing result to the inverter.
(See Fig 3-1.)
The relay sequence function enables the inverter to perform itself in 28 steps without a PLC.
Because the function uses internal data and signals directly, the processing speed is faster than
control with the PLC.
Furthermore, the function enables the inverter to use its multi-function input and output signals
at the same time, and thus to perform various operations in a reduced number of steps.
From external
devices
To external
devices
Fig. 3-1 Signal flow between PLC and inverter
«Example» Start forward run with a push switch (non self hold switch).
● Input and output symbols
● Timing chart
PLC
X1
X2
Q1
Q2
Program
Stop automatically if the output current is 120% or more of the rated current when
the output frequency is 5Hz or less.
For the sake of simplicity, stop signal input terminals are omitted here.
See Example 6 in Chapter 5 for details.
5Hz
Output frequency [Hz]
IX1 input
120%
Output current
Internal operation signal
Inverter
F
S1
RY
OUT
Fig. 3-2 Signal flow of inverter with
IX1 Inverter
F
CC
- 4 -
E6581865
Inverter
From external F
devices
S1
RY
To external
devices
OUT
Setting of My function-S
parameters
My function-S