6
PRE-OPERATIONAL PROCEDURES AND SETTINGS
6.4 Unit Tests
6.4.2 Self-loopback test
6
- 8
1
O
VER
VIE
W
2
SYS
T
E
M
CO
NF
IG
U
R
A
T
IO
N
3
S
P
E
CIFICA
TI
ONS
4
MODB
US
(R)
S
TA
NDA
RD
FUN
C
TIO
N
S
5
FUNC
TI
ON
6
PR
E
-O
PER
A
T
ION
AL
P
R
OCED
URE
S A
ND
SE
TTINGS
7
P
A
RA
MET
E
R S
E
TTI
N
G
8
UTIL
ITY P
A
CK
AGE
(G
X Co
nf
ig
u
rat
o
r-M
B)
6.4.2 Self-loopback test
The self-loopback test checks the send/receive function of the QJ71MB91 and
communications with the programmable controller CPU.
(1) Self-loopback test procedure
* 1 This is the cable wiring for self-loopback test.
Figure 6.6 Self-loopback test procedure
Figure 6.7 Cable wirings for self-loopback test
Start
STOP the programmable controller CPU.
Disconnect the communication cable connected to
the target device.
Connect a cable for self-loopback test.*1
Make the communication
speed/transmission settings. (Switch 2, 4)
Set it to the self-loopback test mode.
(Switch 1, 3 = 000D
H
, 000E
H
combination)
Reset the programmable controller CPU.
Loopback test execution
(approx. 1 second per cycle)
Normal/Error
ERR.LED ON: Error completion
ERR.LED OFF:
Normal operation
End
Monitor the buffer memory and check the
error.
RD
SD
1
2
3
4
5
6
7
8
9
SDB
RDA
RDB
SG
SDA
FG
FG
QJ71MB91
CH1(RS-232)
Signal name
Pin No.
SG
Output for cable
disconnection
detection
Input for cable
disconnection
detection
QJ71MB91
CH2 (RS-422/485)
Signal name
Summary of Contents for QJ71MB91
Page 1: ......
Page 2: ......
Page 366: ...App 14 Appendix 4 External Dimensions APPENDICES Memo ...
Page 371: ......
Page 372: ......