To Connect External Devices - KYOWA WGA-680A Instruction Manual

2-2-5. TO CONNECT EXTERNAL DEVICES

(1) Connection cables
● To connect PCs, etc., use the RS-485 ↔ RS-232C converter, etc.
● The Pin No. 1 and pin No. 2, the pin No. 3 and pin No. 4 have the same function. Use them for transition
wirings.
● Be sure to connect a terminator in the device, located at the end of the transmission line. You are able to short-
circuit the pin No. 6 and pin No. 9 of the WGA-680A-03 instead of connecting the terminator 120 ohm.
● Make sure the RS-485 ↔ RS-232C converter switch is [DTE].
Product side
+ (non-inverting A)
+ (non-inverting A)
- (non-inverting B)
- (non-inverting B)
SG
TERMINATOR
N.C.
N.C.
TERMINATOR
NOTE
Before connecting cables, be sure to turn OFF the product and external devices.
Or, it may cause deterioration or trouble.
(2) To set external devices
Make sure the settings of the external device matches the WGA-680A-03 specifications.
The RS-485 transceiver of the WGA-680A-03 has the fail-safe function. While receiving data, the fail-safe
function makes the CPU output (RO) "1: High" when the circuit, between the pin No. 1 [+ (non-inverting A)] and
pin No. 4 [- (non-inverting B)], is short circuit or open.
While receiving data, the circuit, between the pin No. 1 [+ (non-inverting A)] and pin No. 4 [- (non-inverting B)],
are short circuit. Therefor, when the external device transceiver does not have the fail-safe function, some CPU
output (RO) is "0: Low."
To receive the data correctly, be sure to use the transceiver with the fail-safe function on the converter side.
Product side RS-485 circuit
Logic table
INPUT
/RE DE
0 1
0 1
X 0
1
2
3
4
5
6
Short circuit = With terminator
7
8
9
[Tx]
OUTPUT
DI B
1 0
0 1
X Hi-Z Hi-Z
Converter
TD/RD+
TD/RD-
GND
INPUT
A /RE DE
1 0 0
0 0 0
0 0
0 0
15
IM-A-1060G
PC side
RS-232C
[Rx]
OUTPUT
A－B
RO
≧300mV 1
0
≦-300mV
OPEN 1
SHORT 1