Siemens SINUMERIK 840C - Manual (Page 615)

09.95 8 PLC Machine Data (PLC MD)
8.5 PLC MD for the operating system (system bits)
6049, bit 2 = 0 PLC minimum cycle time switched on (default setting).
6049, bit 2 = 1 PLC minimum cycle time switched off, i.e. the PLC cycle time is derived
from the running time of the user program.
If the PLC minimum cycle time is switched off with PLC machine data
6049, bit 2, the user himself must maintain the VDI signals for at least
twice the IPO sampling time.
6050
DL 25
OB 7 OB 6 OB 5 OB 4 OB 3 OB 2
PLC MD
DB63
DW No.
Bit No.
7 6 5 4 3 2 1 0
Disable
Default value: 1111 1100
Bit 2-7 Bit = 0 The OB referred to is enabled for processing.
Bit = 1 The OB is disabled for processing and is not invoked by the system
program.
6051
DR 25
Program-
mer mode
Special
mode
PLC MD
DB63
DW No.
Bit No.
7 6 5 4 3 2 1 0
Default value: 0000 0011
Bit 1 Bit = 0 The programmer displays 155U as CPU identifier
Bit = 1 The programmer displays 135 WB as CPU identifier
See Section 3
For OB 5, also see PLC MD 2
For OB 2, also see PLC MD 30, 6032 and 6055
Bit 0 Bit = 0 Level change possible after each STEP 5 statement (special mode).
Bit = 1 Level change (e.g. OB 6 interrupts OB 1) possible at block boundaries
only (same performance as 130 WB PLC in normal mode).
Note:
You must set the bit for "PLC mode" to 0 if OB 2 and OB 5 are to be invoked. If this
bit is "1", the OBs are not processed even if they have been loaded into the
programmable controller.
© Siemens AG 1992 All Rights Reserved 6FC5197- AA50 8–23
SINUMERIK 840C (IA)