Siemens SINUMERIK 840D sl Function Manual page 237

time ≥ 5 * F_DP clock cycle of the slower component of the SPL connection with F_DP clock
cycle = $MA_SAFE_SRDP_IPO_TIME_RATIO * IPO clock cycle.
For more complex PLC user programs, it is possible that the parameterized F_ DP clock cycle
is either briefly or even permanently exceeded. This is the reason that for diagnostic purposes,
the maximum value of the F_DP clock cycle since the last time the control booted (powered-
up) is displayed in machine data $MA_INFO_SAFE_SRDP_CYCLE_TIME and in the
diagnostics screen "SI communication".
MD13340 $MN_SAFE_RDP_ENABLE_MASK: Enable screen form
The individual parameterizing data sets are enabled using the enable screen form. The enable
screen form is bit orientated, i.e. bit 0 activates the 1st parameterizing data set with machine
data index 0. If a parameterizing data set is not activated, then the machine data of the
corresponding SPL connection are not evaluated.
The enable screen form is set using MD13340 $MN_SAFE_RDP_ENABLE_MASK.
MD13343 $MN_SAFE_RDP_CONNECTION_NR: Connection number
A parameterizing data set is assigned to an SPL connection using the connection number. A
max. of 16 SPL connections can be parameterized for F_RECVDP. As a result, the value range
for the connection number obtained is: 1, 2, 3, ..., 16.
In the default setting, a parameterizing data set is not assigned to any SPL connection
(connection number = 0). Each active parameterizing data set must be assigned to an SPL
connection. In the case of an error, Alarm 27034 "Parameterization of MD %1[%2] invalid" is
displayed.
The connection number is, at the same time, also the index to access system variables of the
user interface of the SPL connection. The user interface involves the following system
variables:
Input data
$A_FRDP_SUBS[1...n]
$A_FRDP_ERR_REAC[1...n]
Output data
$A_FRDP_ERROR[1...n]
$A_FRDP_SUBS_ON[1...n]
$A_FRDP_ACK_REQ[1...n]
$A_FRDP_DIAG[1...n]
$A_FRDP_SENDMODE[1...n]
The connection number is set using MD $MN_SAFE_RDP_CONNECTION_NR.
Example:
The 3rd SPL connection should be used.
● $MN_SAFE_RDP_CONNECTION_NR[x] = 3
Safety Integrated
Function Manual, 12/2017, 6FC5397-4BP40-6BA1
8.4 Safety-related CPU-CPU communication (F_DP communication)
Connecting sensors and actuators
237