Send Query, Receive Response - Hitachi EH-150 Series Applications Manual

6.3.4

Send Query, Receive Response

 The TRNS 9 command s-parameter at time of query transmission
Command (specified as s+7) of query sending is H0080
Return code
s
System area (6 words)
H 0 0 8 0 (Command)
s+7
Command timeout time
s+8
s+9 Top I/O address of
s+B Top I/O address of
Size of receiving data area
s+D
Figure 6.27 s parameter format (Modbus master / Query transmission)
 Execution of query transmission
After setting each parameter in Fig. 6.27 to s parameter area and storing the query parameter in the sending data
area, please turn ON the command execution flag (t+0). (The format of the query data area depends on function
code.)
 Response receiving
Response data is automatically stored receiving data area with completion flag being ON. (In modbus master mode,
one cycle of TRNS 9 command is from sending to receiving.)
When any errors from the slave response are detected or an exception response is returned, an error flag (t+2) turns
on. The exception response data (exception code) is stored in the receiving data area.
« Note »
EH-SIO checks the validity of the response code, the function code, and the check code only. Therefore, if the
above-mentioned item is correct, the data are stored in receiving data area even if more data than requested is
received.
The execution result of TRNS 9 command is displayed.
(Set by the system.)
The command at the time of query transmission is H0080.
For sending query.
sending data area
For response data.
receiving data area
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Chapter 6 Communication Mode