Hitachi EH-150 Series - Initial Setting

Chapter 6 Communication Mode
6 - 31
Modbus Master
6.3.3 Initial setting
When power is turned ON, EH-SIO will be in idle state (initial setting waiting from CPU module). Operation in
modbus master mode is started by initial setting from CPU module.
In addition, once initial setting is completed, the setting cannot be changed, unless CPU module is stopped or
EH-SIO is reset.
« Note »
In there is no initial setting, EH-SIO will not receive any other command from CPU module and external device
than initializing command.
 Parameters for initial setting
Table 6.8 Parameters list for initial setting
No.
parameter
Contents
1
Communication mode
Be sure to set modbus master mode (H0010).
2
Modbus transmission mode
Select RTU mode (0) or ASCII mode (1).
Only RTU mode is supported by software ver. 1.0.
3
Receiving timeout interval
Specify timeout if necessary.
The definition of timeout is as follows.
[1] No response with in specified time.
[2] Data receiving not completed within specified time.
 s parameter of TRNS 9 command for initial setting
Initializing command (specified as s+7) is H0000.
Although nothing is stored in the receiving data area specified by s+B to s+D upon the performance of the
initial-setting command, each parameter needs to be specified.
Figure 6.24 s parameter format (Modbus master / Initial setting)
Size of receiving data area
Top I/O address of
receiving data area
Return code
H0000 (Command)
Command timeout time
Top I/O address of
sending data area
s
s+7
s+8
s+9
s+B
s+D
System Area ( 6 words )
Set by user
Dummy parameter