MITSUBISHI ELECTRIC QJ71C24N - Manual (Page 107)

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MELSEC-Q
4 SETTINGS AND PROCEDURES PRIOR TO OPERATION
(2) Restart the PLC CPU station or reset the CPU. The test starts automatically in
about one second.
(3) For the Q series C24, the following tests should be performed once.
1) ROM check
Read the ROM data and verify the sum check.
2) RAM check
Write data to RAM, and read and check it.
3) Switch check
Check whether or not each switch is set within the tolerance range and the
operation setting in the transmission settings is set to off.
4) Linked operation setting check (perform this test with the operation setting in
the transmission settings of CH2 set to on)
Check to see that the communication protocol setting on CH1 is set to 8
H
and
whether the communication rate setting of each channel is within the tolerance
range.
A linked operation setting check is performed when values are set as follows:
• Communication protocol setting on the CH1 side : 8 H
• Operation setting in the transmission settings on the CH2 side: bit 8 = ON.
(Procedure 3) Checking results of ROM/RAM/switch tests
(1) The test is completed when the NEU LED on CH1 side is lit (approximately 2
seconds).
(2) The test is completed normally when the ERR LED turns off.
(3) The test is completed with error when the ERR LED turns on. Check the error
description in one of the following screens.
• The "Monitor/test others" screen of GX Configurator-SC (see Section 8.6.9)
• The buffer memory monitor screen of GX Developer (see the GX Developer
Manual for the operation method)
When checking errors in the buffer memory monitor screen of GX Developer,
monitor the following buffer memory.
Check the error descriptions on the screens by bit-decoding the monitored value
(16-bit integer). Each bit corresponds to the following error description.
Buffer memory monitored
Address
Bit location
CH1 side
201
H
CH2 side
202
H
CH1/CH2 side
203
H
Description when corresponding bit is on Corrective action
b0 — — —
b1 SIO — Transmission setting error
b2 PRO —
When linked operation
setting Protocol setting error
b3 P/S — Transmission setting error
b4 C/N —
When independent
operation setting Protocol setting error
Review setting value
(see Section 4.5.2)
b5 to b6 — — — —
b7 NEU — Test completed —
b8 to b13 — — —
CH2 ERR — RAM error ( 1)
b14
—
Setting station
number
Out of the setting station number range
Review setting value
(see Section 4.5.2)
b15
—
CH1 ERR — ROM error ( 1)
1 Consult your nearest dealer.