Siemens SINUMERIK 840Di Function Manual page 1431

Data Lists
5.1 Machine data
5.1
5.1.1 NC-specific machine data
Number Identifier: $MN_
10100 PLC_CYCLIC_TIMEOUT
14504 MAXNUM_USER_DATA_INT
14506 MAXNUM_USER_DATA_HEX
14508 MAXNUM_USER_DATA_FLOAT
14510 USER_DATA_INT
14512 USER_DATA_HEX
14514 USER_DATA_FLOAT[n]
Machine data in integer/hex format is operated in the NC as DWORD.
Machine data in floating comma format are operated in the NC as FLOAT (IEEE 8 byte).
They are stored in the NC/PLC interface and can be read by the PLC user program during PLC power-up from the DB 20.
5.1.2 Channel-specific machine data
Number Identifier: $MC_
28150 MM_NUM_VDIVAR_ELEMENTS
PLC Basic Program Solution Line (P3 sl)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0
Description
Cyclic PLC monitoring time
Number of user data (INT)
Number of user data (HEX)
Number of user data (FLOAT)
User data (INT)
User data (HEX)
User data (FLOAT)
Description
Number of elements for writing PLC variables
5
5-1