B

Start Program

ID 08

Reply:

ID 08 stat_high stat_low

stat_high

± High byte of status word

stat_low

± Low byte of status word

Status Word:

bits 0 ± 7 are for fatal conditions (stopping the PLC) bits 8 ± 11 are for non-fatal conditions

bit 15 is informational

0memory is corrupted

1invalid program

2invalid instruction encountered

3(runtime error (such as Indirect Move to invalid address)

4 ± 6

reserved

7forced stop (PLC stopped by error or by programmer)

8I/Oproblem

9system timer malfunction

10 ± 14

reserved

15

Program mode (1 if in Program mode)

Stop Program

ID 09

Reply:

ID 09 stat_high stat_low

stat_high

± High byte of status word

stat_low

± Low byte of status word

Error Reply

ID 8x error_code

8x is the command code to which this is the reply plus 128 (80h).

error codes:

1Receive buffer overflow

2Checksum error

3Illegal command code

4Illegal command format

5Block size too big or zero

6Cannot modify program while running

7Cannot run while switch is in PROG position

8Address out of range

GFK±0804B

Appendix B Micro PLC Protocol

B-7

Page 95
Image 95
GE GFK-0804B manual Start Program, Stop Program, Error Reply, Error codes