CHAPTER 6 USING THE COMMUNICATIONS FUNCTION
E5AK
6--4
·
Up to 32 controllers including a computer can be connected to the host
computer.
·
The total cable length should not exceed 500 meters.
·
Use shielded twisted-pair cables (AWG28 or more) for the cables.
·
Attach terminators to the controllers at both ends of a series of control-
lers connected in an open configuration. For example, in the following
configuration, connect the terminator to the host unit and the unit
No.30, and do not connect terminators to unit Nos.0 to 29.
·
Use terminators having a resistance of 120
W
(1/2 W). The total resis-
tance of both ends should be at least 54
W
.
-
+
FG
RS-485
No.
32
31
RS-485
No.
32
A
B
31
Host computer
RS-485
Shielded cable
E5AK (No.0)
E5AK (No.30)
Terminator
(120
W
1/2W)
A
B
A < B : Mark
A > B : Space
19
20
A
B
19
A
B
20
Match the communications specifications of the host computer and E5AK
controller. When two or more controllers are connected to the host com-
puter, make sure that the communications specifications of all controllers
are the same.
This section describes how to set the communications specifications of the
E5AK controller. For details on the host computer, see the relevant manual
supplied with the host computer.
Set the communications specifications of the E5AK in the controller’s
communications parameters. The communications parameters are set on
the front panel of the E5AK controller.
The following table shows the communications parameters (option mode)
provided on the E5AK controller and their respective settings.
Parameter/Symbol
Setting
Set Value
Unit No.
0 to 99
0
to 99
Baud rate
1.2/2.4/4.8/9.6/19.2 (kbps)
1.2/2.4/4.8/
9.6
/19.2
Bit length
7/8 (bit)
7
/8
Parity
None/even/odd
/
/
Stop bit
1/2
1/
2
Inverted items are factory-settings.
F
RS-485
J
Setting the com-
munications
specifications
F
Communications
parameters