14. COMMUNICATION FUNCTION 
14 -  7 
 
14.3.3 Error codes 
Error codes are used in the following cases and an error code of single-code length is transmitted. 
Receiving data from the master station, the slave station sends the error code corresponding to that data to 
the master station. The error code sent in upper case indicates that the servo is normal and the one in lower 
case indicates that an alarm occurred. 
 
Error code 
Servo: normal  Servo: alarm 
Error name  Explanation  Remarks
[A]  [a]  Normal  Data transmitted was processed normally.  Positive 
response
[B]  [b]  Parity error  Parity error occurred in the transmitted 
data. 
[C]  [c]  Checksum error  Checksum error occurred in the 
transmitted data. 
[D]  [d]  Character error  The transmitted character is out of 
specifications. 
[E]  [e]  Command error  The transmitted command is out of 
specifications. 
[F]  [f]  Data No. error  The transmitted data No. is out of 
specifications. 
Negative 
response
 
14.3.4 Checksum 
The checksum is an ASCII-coded hexadecimal representing the lower two digits of the sum of ASCII-coded 
hexadecimal numbers up to ETX, with the exception of the first control code (STX or SOH). 
STX
or
SOH
ETX Check
Checksum range
Station No.
 
[5][2]
STX
30H + 41H + 31H + 32H + 35H + 46H + 03H
= 152H
[0] [A] [1] [F]
[5] [2]
ETX
02H 30H 41H 31H 32H 35H 46H 03H
Lower 2 digits 52 is sent after conversion into ASCII code [5] [2].
14.3.5 Time-out processing 
The master station transmits EOT when the slave station does not start return processing (STX is not 
received) 300 [ms] after the master station has ended communication processing. 100 ms after that, the 
master station retransmits the message. Time-out occurs if the slave station does not answer after the 
master station has performed the above communication processing three times. (communication error) 
Message
300 ms
Controller side
(master station)
Servo side
(slave station)
EOT
100 ms
Message
300 ms
EOT
100 ms
Message
300 ms
EOT
100 ms
Message
300 ms
*Time-out