Error codes
Section 5-2
93
5-2
Error codes
Reporting errors
The errors that can occur at the Unit are divided in 6 categories: DM-configuration
errors, IOWR-instruction errors, overflow/underflow errors, Preset error, Interrupt-
FIFO full error and System errors. Every error is assigned a unique error code.
The
error code
consists of two words (error code 1 and error code 2). At the occur-
rence of an error:
• the corresponding
error code
is transferred to words n+15 (=error code 1)
and n+16 (=error code 2) of the Special I/O Unit Area in CIO-memory
• the corresponding
error code
is stored inside the Counter Unit
• the Global Error bit in CIO is set (n+17 / bit 00)
• the ERC-LED is turned ON
After you have cleared the error:
• words n+15 (=error code 1) and n+16 (=error code 2) are reset
• the Global Error bit in CIO is reset (n+17 / bit 00)
• the ERC-LED is turned OFF
Every error category requires its own unique action to clear them (refer to section
the next sections for information on clearing errors of different categories).
n+16
Error Code 2
General Setting:
n+15
Error Code 1
n+17
Global Error bit:
0 = No error exists
1 = Error(s) has/have occurred
15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
