Siemens SINUMERIK 840D Description Of Functions page 254

4 Data Descriptions
4.2 Machine data for SIMODRIVE 611 digital
If the actual checksum does not match the setpoint checksum in MD 1399:
$MD_SAFE_DES_CHECKSUM, then the Alarm 300744 "Checksum error safe
monitoring" is displayed.
1399 $MD_SAFE_DES_CHECKSUM
Checksum of machine data for safety functions
Unit: Default:
00 00 00 00
This data contains the setpoint checksum of the actual values of the SI
machine data that was saved during the last machine acceptance test.
After POWER ON, the actual checksum is calculated, entered into MD 1398:
$MD_SAFE_ACT_CHECKSUM and compared with the setpoint checksum in
this data.
If the values are not identical, data has either been changed or there is an error
and Alarm 300744 "Checksum error safe monitoring" is displayed.
4-254
SINUMERIK 840D/SIMODRIVE 611 digital SINUMERIK Safety Integrated (FBSI) - Edition 11.03
Minimum value: Maximum value:
00 00 00 00 FF FF FF FF
611digital
Relevant for:
FD/MSD
Data type: Becomes effective:
Long integer POWER ON
© Siemens AG 2003 All Rights Reserved
11.03