Omron E5ZD, Руководство по эксплуатации

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6-2 Loop-Back Communications Test
When there are problems with communications, the loop-back communications
test can be used to see if the E5ZD is operating properly. For this test, the E5ZD
transmits data out and then directly back into itself to see if the same data is re-
ceived. The character string sent for the test, shown below, is sent continuously
and can therefore also be received by the host computer. Once test communica-
tions have started, the string will continue to be sent until the power is turned off.
E5ZD-4/-6
jjj
-E:
E5ZD
Ć
Copyright
Ć
1990
Ć
OMRON
Ć
Corporation
s
(Carriage return)
E5ZD-8
jjj
-E:
E5ZD
Ć
Copyright
Ć
1991
Ć
OMRON
Ć
Corporation
s
(Carriage return)
E5ZD-8H
jj
M-E:
E5ZD
Ć
Copyright
Ć
1991
Ć
OMRON
Ć
Corporation
s
(Carriage return)
Loop-back Test To prepare for the loop-back test, wire the pins of the communications connector
for your model as shown below for RS-232C and RS-422 communications. For
RS-485 communications, no special wiring is required because the required
pins are connected internally; just turn ON pin 1 of SW5. Set the operation mode
to “Test” with the DIP switch.
Connect
pins 2 and 3. Connect pins 6 and 9,
and pins 1 and 5.
E5ZD
RS-422
Symbol
SDA
SDB
RDA
RDB
SG
Pin
9
5
6
1
3
1 FG
7 SG
2 SD
3 RD
4 RS
5 CS
6 DR
20 ER
Pin
E5ZD
RS-232C
Sym-
bol
After finishing the above preparations, just turn on power to the E5ZD to start the
test. The E5ZD’s error output terminal will go ON and the error indicator will light
when errors are found in the received character string. When the carriage return
is reached in the string, the error output terminals will go OFF and then transmis-
sion of the string will begin again.
To receive and check the test at the host computer, set the baud rate and other
transmission parameters and connect the host computer and E5ZD with a com-
munications cable. Set up the computer to receive the data, set the operation
mode to “Test” on the DIP switch, and then turn on the E5ZD to start transmission
of the test data. The test will proceed as described above. Because the E5ZD is
not receiving the test character string, the indicator will light and the alarm output
will go ON, but these can be ignored. If processing is slow at the host, the host’s
receiving buffer may fill up. If this happens, slow down the transmission speed. Receiving at the Host
Computer
Loop-Back Communications Test
Section 6-2