Siemens Sinumerik 840D Series Function Manual page 155

02.99
10.03
Threshold
input field
Fig. 4-21 Variable signaling function
 Siemens AG, 2003. All rights reserved
SINUMERIK 840D/SIMODRIVE 611 digital, HLA Module (FBHLA) - 10.03 Edition
Any memory location from address space X or Y in the data RAM can be moni-
tored for violation of a set threshold for the variable signaling function. A toler-
ance band can be set around this threshold; this is taken into account when the
threshold is scanned for violation in either direction. Any violation of the toler-
ance band is signaled to the PLC. This violation message can be linked to a
pickup and/or dropout delay. The signaling function operates in a 4 ms cycle.
ON delay time
Note
The quantity to be monitored can be selected through specification of either a
signal number or a physical address, the physical address having relevance
only for Siemens servicing activities.
The following machine data corresponds to MD 5620:
S
MD 5621: PROG_SIGNAL_NR
S
MD 5622: PROG_SIGNAL_ADDRESS
S
MD 5623: PROG_SIGNAL_THRESHOLD
S
MD 5624: PROG_SIGNAL_HYSTERESIS
S
MD 5625: PROG_SIGNAL_ON_DELAY
S
MD 5626: PROG_SIGNAL_OFF_DELAY
Note
If changes are made to machine data MD 5621 to MD 5624 while monitoring is
8
already active ( MD 5620, Bit 0 = 1), they do not automatically reinitialize the
PLC message, i.e. reset it to 0. If the message must be re-initialized, the
monitoring function must be switched off and on again via MD 5620, bit 0, after
the MD setting has been changed.
4 Firmware Drive Functions
4.13 Monitoring functions
Message to PLC
OFF delay time
Tolerance band
t
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