Hitachi EH-150 Series - Configuration of Slave Station

Chapter 6 Communication mode
6 - 99
Simple data link
6.6.5 Configuration of slave station
(1) In case of EH-CPU as slave station
Configure port 1 of EH-CPU as RS-422 transmission procedure 2 with station number.
Step 1 : Set Dip Sw of EH-CPU at the bottom according to transmission speed of EH-SIO.
Step 2 : Set parameter in special internal output WRF037 according to the table 6.27.
Table 6.27 Configuration of EH-CPU communication port
WRF037
Interface
User value
System value
*1
Indication after power up
HE1**
H61**
H65**
Built-in termination register
*2
is disabled
HF1**
H71**
H75**
Built-in termination register
*2
is enabled
｢**｣ means the station number. Setting range is from 00 to 31, and set by BCD. If the setting value is out of range, the CPU
module operates as the station number 31 though displays number keeps setting value.
*1 : Bit11 and bit10 of WRF037 shows the current interface. Therefore, depending on the previous setting, the system value
may be displayed in different values. As to the details of these bits, please refer to the EH-CPU application manual.
*2 : EH-CPU516/548 has built-in termination register. If built-in termination register is enabled, it is no need to put external
termination register.
« Note »
 CPU module which has not RS-422 interface and transmission procedure 2 can’t be used as slave station.
 Implement wiring according to RS-422 interface.
 It is possible to use RS-485 instead of RS-422, but the protocol error (error code 6A) may be detected during the
communication. (The operation will be continued even if this error code is displayed.)
(2) In case of MICRO-EH as slave station
Configure port2 of MICRO-EH as transmission procedure 2 with station number.
Set the parameter in special internal output WRF03D referring table 6.28.
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
WRF03D :
a
b
c
0
d
e
Initial value
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Figure 6.70 Special internal output of port2 configuration
Table 6.28 Configuration of EH-CPU communication port
Area
Value
Contents
Remark
a
0
Indicate after setting
After setting, system set zero.
1
Request change of setting
When requesting change of setting, one is set
b
0
Transmission procedure 1
1
Transmission procedure 2
c
0
Without station number
1
With station number
d
0
Transmission speed
4800 bps
Bit pattern b8 to b11 is
H0000
1
9600 bps
H0001
2
19.2 kbps
H0010
3
38.4 kbps
H0011
Except above
4800 bps
e
0 to 31
Station number*
Specify by BCD
« Note »
 MICRO-EH (10 points and 14 points) can’t be used as slave station because it has not RS-422 port.
 Implement wiring according to RS-422 interface.