RKC INSTRUMENT COM-JG, Инструкция по эксплуатации

Страница: 74 / 126

8. USAGE EXAMPLE
IMR01Y35-E3
68
Static data read/write range
Overview
The static data read/write range can be set to prevent the reading of unneeded data and the writing of
incorrect data.
When a communication item is specified in a static data request, a read or write request is normally
sent to the same Modbus register address of all connected controllers (each module of the SRZ).
For this reason, when modules that have different Modbus register addresses are connected and a
communication item is specified, the wrong data may be read or data may be written to other than the
intended communication item (depending on the module).
For example, when a Z-TIO module and a Z-DIO module of an SRZ are connected and a
communication item of the Z-TIO module is read, the data of the same Modbus register address
in the Z-DIO module as the communication item specified in the Z-TIO module is read. However,
because the contents of the Modbus register addresses of the Z-TIO module and the Z-DIO
module are different, different data is read from each.
Example Z-TIO module: 006DH
→
RUN/STOP transfer
Z-DIO module: 006DH
→
DO minimum ON/OFF time of proportioning cycle
To avoid having unnecessary data read, the range of data that can be communicated for the same
module type can be assigned.
Setting contents
Five channels each can be set for read and write. This means that five different types of Modbus
register addresses can be handled.
For each channel, set the number of connected modules that have the same Modbus register address
and the number of communication items.
Data range: 0 to 65535 (Factory set value: 0)
The “Number of connected modules” is set in the upper hexadecimal byte, and the
“Number of communication items” is set in the lower byte.
This setting is not necessary when the controller consists only of modules that are the same
type.
For Modbus register address of the SRZ, refer to 7. COMMUNICATION DATA MAP
(P. 28) .