Hitachi EH-150 Series - Hi-Protocol Mode; Basic Function

Chapter 6 Communication mode
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Hi-Protocol
6.5 Hi-Protocol mode
Hi-Protocol mode is a passive communication mode for EH-SIO. EH-SIO sends response command to a host
computer according to the received request command from the host computer. This communication protocol between
host computer and EH-SIO is dedicated communication procedure for H and EH series. (A request issued by host
computer is called “request task code” and a response sent by EH-SIO is called “response task code”.)
The operation mode is configured by TRNS9 command in user program. Once this mode is configured (initial setting)
properly, the other communication program is not required anymore because the system software of EH-SIO will takes
care this communication operation except initial setting.
« Remark »
As for the communication procedures for H / EH series, there are two procedures, a standard procedure (transmission
control procedures 1) and a simple procedure (transmission control procedures 2). EH-SIO software ver. 2.0 is
supporting procedures 1 only. EH-SIO of software ver. 2.1 is supporting both of communication procedures.
6.5.1 Basic function
After mode setting (initial setting) is completed, EH-SIO will be the status of “Waiting request task code”.
If EH-SIO receive request task code from host computer, EH-SIO decodes the request task code and transfers the
request to CPU module. When EH-SIO receives the response from CPU module, EH-SIO sends back the response
to host computer according to the Hi-Protocol message frame procedure.
Figure 6.55 Hi-Protocol basic function
 Table of task code supported by EH-SIO
Following table shows the supported request task code with EH-SIO. The detailed request task code specification is
described in “A.3.4 EH-SIO support task code details”
Table 6.19 Supported task code
Command
Contents of function
10H
Read CPU status
16H
CPU occupation / release
17H
Forced release of occupation
40H
Read I/O (series N points) (Read occupation required)
42H
Write I/O (series N points) (Read occupation required)
44H
Read I/O (random N points) (Read occupation required)
45H
Write I/O (random N points) (Read occupation required)
A0H
Read I/O (series N points) (Read occupation not required)
A2H
Write I/O (series N points) (Read occupation not required)
A4H
Read I/O (random N points) (Read occupation not required)
A5H
Write I/O (random N points) (Read occupation not required)
« Note »
Programming software and equipment cannot operate via EH-SIO even if the communication mode
specified Hi-Protocol mode since the special task codes for programming software are not supported by
EH-SIO.
HMI etc.
Request
Request task code
Response task code
No need of user program
Response