Siemens SINUMERIK 840D sl Function Manual page 266

Connecting sensors and actuators
8.5 Safe programmable logic
It is only possible to work with a restricted language scope in order that SAFE.SPF can be
started in spite of the fact that alarms are active. The PLC or drives cannot be accessed. For
commands, which are not included in the language scope, Alarm 15420 "Channel%1 %2
Instruction in the current mode not allowed" is output.
If it is required to change over an existing SAFE.SPF to the restricted language scope, then it
is possible to proceed as follows:
● MD20108 $MC_PROG_EVENT_MASK, bit 5=0
● MD10095 $MN_SAFE_MODE_MASK, bit 2=1 (as a result, for SAFE.SPF, the reduced
language scope is activated - also as a result of the CALL call)
● Call SAFE.SPF in MDI (CALL "/_N_CST_DIR/_N_SAFE_SPF")
● SAFE.SPF is edited until the program can be executed without any alarms with the
restricted language scope.
● MD $MC_PROG_EVENT_MASK, bit 5=1; SAFE.SPF is called when booting and is
executed error-free with the restricted language scope.
Starting the NCK-SPL via PROG_EVENT
Note
This function is an option, and is not included as standard in Safety Integrated.
The NCK-SPL can also be started using the PROG_EVENT mechanism.
The PROG_EVENT.SPF cycle (saved under manufacturer cycles ..\DH\CMA.DIR) is started
when a specific event occurs (event-controlled program call).
Using machine data MD 20108 $MC_PROG_EVENT_MASK, for this PROG_EVENT
mechanism, certain events are enabled on a specific channel-for-channel basis, which then
start the cycle.
The start condition when booting (bit 3 ==1) must be active in order to start the NCK-SPL
(SAFE.SPL) via PROG_EVENT.SPF.
Note
When starting the NCK-SPL (SAFE.SPF), it is important that the PROG_EVENT mechanism
was started through channel 1. This must be taken into account when parameterizing the
channel-specific machine data MD20108 $MC_PROG_EVENT_MASK.
Using the system variable $P_PROG_EVENT, in PROG_EVENT.SPF it can be interrogated
as to which event activated the call:
● Part program start
● Part program end
● Operator panel reset
● Booting
266
$P_PROG_EVENT == 1
$P_PROG_EVENT == 2
$P_PROG_EVENT == 3
$P_PROG_EVENT == 4
Function Manual, 12/2017, 6FC5397-4BP40-6BA1
Safety Integrated