IDEC MicroSmart Pentra - Manual (Page 46)

D EVICE A LLOCATION OF PID M ODULE
FC5A MicroSmart PID Module User’s Manual FC9Y-B1283 5-5
Examples of changing the PID module parameters using the control relay
All parameters of block 1 to 5, 10 to 19, and 30 to 39 can be changed using a ladder program. The following
examples demonstrate how the parameters of the PID module can be changed. See pages 5-7 to 5-24 for
detail about each block parameter.
Example 1: Changing Block 1 Parameter
The set point (SP) of CH0 control (D1020) is changed to 250.5°C. In this example, D1000 is allocated to the
control register and M500 is allocated to control relay.
When the new set point 2505 is stored in D1020
*1
, it is automatically written to the PID module
*2
.
Ladder Program Example:
When external input I0 is turned on, the set point (SP) of CH0 will be changed to 250.5°C.
*1: When the input range has a decimal point, store the value multiplied by 10 in the data register.
*2: When the control register is D1000, Block 1 parameters are stored in D1020 to D1025. These values are written to
the PID module every scan.
Example 2: Changing Block 2 Parameters
The integral time (D1027) is changed to 150 seconds and the derivative time (D1028) is changed to 45
seconds for CH0 control. In this example, D1000 is allocated to the control register and M500 is allocated to
control relay.
Those parameters can be changed with the following procedure.
1. Turn on M500 (Reading all parameters). All PID module parameters are read out from the PID module
and stored in the data registers.
*1
2. Store 150 in D1027 (integral time of CH0) and 45 in D1028 (derivative time of CH0).
3. Turn on M503 (Block 2 writing)
*2
. The integral time (150 sec) and derivative time (45 sec) will be written
to the PID module.
Ladder Program Example:
*1: If the reading all parameters bit (M500) is turned on, all PID module parameters are read out from the PID module
and stored in the data registers. Block 2 parameters are stored in D1026 to D1052.
*2: Block 2 parameters stored in D1026 to D1052 are written to the PID module. The parameters of the other blocks
are not written.
When I0 is turned on, the new set
point 2505 is stored in D1020 [set
point (SP) of CH0].
1st Scan
At the rising edge of M100, M500 is turned on to
read all parameters from the PID module.
M100 is turned off.
2nd Scan
At the falling edge of M100, M500 is turned off.
150 is stored in D1027 (integral time of CH0).
45 is stored in D1028 (derivative time of CH0).
M503 (Block 2 writing) is turned on to write block 2
parameters stored in D1026 to D1052 to the PID
module.