User`s manual

FX communication
Diagnostics 12
12-4
12.4 Computer Link
12.4.1 NAK Error Code
The error code is sent following a NAK response to indicate the type of error that occurred. It is
transmitted as two ASCII characters representing the hexadecimal codes ranging from 00H to
FFH.
If two or more errors occur simultaneously, the error code with the lowest number is transmitted.
12.4.2 Programmable Controller Error Code
With the FX series programmable controllers, the following errors are not transmitted using a
NAK, but instead are shown at the programmable controller by switching on special auxiliary
relay M8063, and storing the error code in special data register D8063.
Because these errors are not transmitted it must be programmed at the computer so as to
recognize an error by using a watchdog timer or other monitor timer.
Error code
(hexadecimal)
Error description
00H, 01H

02H Sum error
03H
Protocol error (the communication protocol does not conform to the format selected
with D8120)
04H, 05H

06H
Character area error (the character area is incorrectly defined, or the specified
command is not available)
07H
Character error (the data to be written to a device consists of ASCII codes other than
hexadecimal codes)
08H
,
09H

0AH PLC number error (the PLC number is not set to “FF” or not available from this station)
0BH to 0FH

10H PLC number error (the PLC number is not set to “FF” or not available from this station)
11H
to
17H

18H Remote error (remote run/stop is disabled)
Error code
(in D8063)
Error description
6301 Parity, overrun, framing error
6305
Command failure receiving a command other than GW (global) when the station
number is “FF”
6306 Monitor timer over (message to be received is insufficient)