IDEC MicroSmart Pentra - Manual (Page 42)

D EVICE A LLOCATION OF PID M ODULE
FC5A MicroSmart PID Module User’s Manual FC9Y-B1283 5-1
5: D
EVICE
A
LLOCATION OF
PID M
ODULE
This chapter describes the valid devices, control registers, control relays, and data register allocation for the
PID module.
Device Allocation of PID Module
The PID module is used by connecting to the MicroSmart CPU module. To use the PID module, allocate the
data register and internal relay to the PID module, configure the initial parameters using WindLDR, and down-
load the user program and the parameters to the CPU module and the PID module. The initial parameters are
downloaded to the CPU module along with the user program. The CPU module reads/writes data from/to the
PID module according to the parameters configured in WindLDR.
The PID module parameters consist of 26 data blocks divided according to the function and frequency of use
of each parameter as shown in the table below. All blocks to be used are allocated to the data registers in the
CPU module. The parameters of each block can be read from/written to the PID module using the allocated
control relays.
Block
Number of Data
Registers
Description
Block 0 20 Read only parameters (CH0, CH1)
Block 1 6 Write only parameters (CH0, CH1)
Block 2 27 Basic parameters (CH0)
Block 3 27 Basic parameters (CH1)
Block 4 50 Initial setting parameters (CH0)
Block 5 50 Initial setting parameters (CH1)
Blocks 10 to 19 21/block Program parameters (CH0)
Blocks 30 to 39 19/block Program parameters (CH1)
Block 0 includes parameters such as operating status, current process variable (PV), set point (SP), and
output manipulated variable (MV) of the PID module. The CPU module reads those parameters from the PID
module every scan. The control status and alarm status of the PID module can be monitored with Block 0
parameters.
Block 1 includes the set point (SP), manual mode output manipulated variable (MV), and operation parameters
of the PID module. Those parameters are written to the PID module every scan. Operations such as changing
the set point (SP) for the fixed value control, enabling/disabling the control, or performing auto-tuning (AT) can
be carried out.
Blocks 2 and 3 include basic parameters of the PID module. By turning the control relay from off to on,
parameters can be read from/ written to the PID module.
Blocks 4 and 5 include initial setting parameters of the PID module. Parameters that are usually not changed
during the operation are stored.
Blocks 10 to 19 and 30 to 39 include parameters of each step of the program control. By turning the control
relay from off to on, parameters can be read from/written to the PID module.
Block data are read from/written to the
PID module according to the settings
configured in WindLDR.
CPU Module PID Module