H 8 - 3
are described in the following
：
Y3
Y2
Y1
Y0
Error
Code
Description
0 0 0 1
1
Application program contains the functions not supported by this
CPU
0
0
1
0
2
Mismatch of PLC ID VS. program ID
0
0
1
1
3
Checksum error in LADDER program
0
1
0
0
4
System STACK abnormal
0 1 0 1
5 Watch-Dog
occurs
0
1
1
0
6
Exceed main unit I/O
0
1
1
1
7
Syntax check error occurs
1
0
0
0
8
Expansion I/O modules over limit
1
0
0
1
9
Expansion I/O points over limit
1
0
1
0
10
System FLASH ROM CRC error
1 0 1 1 11
Reserved
1 1 0 0 12
Reserved
1 1 0 1 13
Reserved
1 1 1 0 14
Reserved
1 1 1 1 15
Reserved
Indicator on Transmit/Receive of Built-In Communication Port (Port0) “TX”
、
“RX”
These two LED indicators are used for the status of transmit/receive of the built-in communication port (Port0). The RX
indicator (green) is for indication when PLC receives external signals, while the TX indicator (red) is for indication when
PLC transmits signals, both of which are very helpful in monitoring communication condition and debugging. When PLC
communicates with external equipment (computer, programmer, intelligent peripherals, etc.), Port0 in FB
S
-PLC can only
be used in slave mode (Port1~4 can be used in master mode). Therefore, during its operation, PLC must first receive
external signals (RX on) before it can transmit signals back to external equipment (TX on now). When the
communication is fail, one can tell if it’s PLC is not receiving signals or PCL is not replying by looking at the these two
indicators. The currents in these two LED are constant and their lighting duration is proportional to the reception or
transmission time. The more received/transmitted data or the slower (bps) reception/transmission, the longer the
reception/transmission time and so is the indication time (brighter visually). If in high speed but small amount of data,
only short and dim brightness is observed. Therefore, the communication condition can be easily distinguished by these
two indicators.
Indicator of Input Status
〝
Xn
〞
When external input Xn is ON, the corresponding LED indicator Xn will be on, otherwise it will be off. If it fails to respond
to external input, please check if the terminal wiring is securely connected, or measure the voltage between
〝
Xn
〞
and
common
〝
C
〞
to see if it has a change of 0V/22V with ON/OFF of input. If it does, it means that an error occurs in PLC
input circuit or LED indicator. Or you can locate the problem by using the monitor mode of the programmer to check if
this input status works correspondingly with the external input state.
Indicator of Output Status
〝
Yn
〞
When the Yn output of PLC is ON, its corresponding output indicator will also be on and its external load will be ON. If
ON/OFF condition of external load is inconsistent with output indicator, please check the wiring of the load, power, and
terminal for secure connection. If the connection is good, then it should be the PLC output component failure. The main
reasons to cause the output component failure are:
1. Overload or short circuit that burns output component and results in permanent open or short circuit.
