Chapter 8 Exercising program
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8.6 Communication with HEX communication equipment
Communication with devices which communicate with GLOFA-PLC through HEX protocol is described as below. HEX
communication needs only half amount of ASCII communication data, so it enables double speed communication
comparatively even in the same communication speed. The figure shows an example of user defined mode
communication of Cnet I/F module as a master station, with temperature controller which performs HEX communication.
12-word data per channel of temperature input 12 channels of temperature controller are read one by one and saved
to %MB300 address of GLOFA PLC, and if No.0 bit input value of slot No.1 input module in GLOFA PLC is turned on, 24
bytes data is read from %MB1000 address and output to 12 channels of D/A output module of temperature controller in
this program example. GLOFA Cnet I/F module and temperature controller perform 1:1 communication via RS-232C
channel in the system configuration as shown in [Figure 8.18].
[Figure 8.18] Communication system of GLOFA-PLC with temperature controller
8.6.1 Exercising program
Cnet I/F module operates as a master station in user defined mode, and temperature controller operated as a slave
responds to Read/Write data requests of GLOFA Cnet I/F module via RS-232C communication port in [Figure 8.18].
For this service, set mode and basic items of Cnet I/F module and then prepare frame and GMWIN program. As
communication protocol of temperature controller is in HEX communication here, HEX value is to be defined in the
frame of Cnet I/F module, which is supported only in Cnet Ver.2.0 or later. Ver.2.0
Remark
[Note1] When setting of constant in Frame Editor, HEX value can’t be input, thus, former modules than Cnet Ver.2.0
are unavailable for the service. Frame Editor also shall be of Ver. 2.0 or later for the service.
Temperature controller
RS-232C interface
GLOFA-PLC