Chapter 6 Communication Mode
6 - 35
Mod
b
u
s M
a
ster
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
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.
Top I/O address of
receiving data area
Size of receiving data area
Return code
H 0 0 8 0 (Command)
Command timeout time
Top I/O address of
sending data area
s
s+7
s+8
s+9
s+B
s+D
For sending query.
System area (6 words)
The command at the time of query transmission is H0080.
The execution result of TRNS 9 command is displayed.
(Set by the system.)
For response data.
Содержание EH-150 Series
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