Spontaneous Messages - Danfoss 5000 Flux Manual

Spontaneous messages

The spontaneous message is triggered by the
active parameters 538, 540 or 953.
The PCV response indicates the parameter number
(PNU) and the parameter value (PVA) of the modi-
fied active parameter that triggered the message.
Spontaneous messages are generated when active
parameters are changed, i.e. a message occurs
when a warning appears and when a warning dis-
appears.
At the same time, the VLT modifies the SPM bit (11)
of the PCV word (see "PCA processing").
The spontaneous messages are transmitted until
the master has confirmed the receipt of the mes-
sage and changed the SPM bit.
Spontaneous messages are only activated
when the parameter 917 is in the "ON"
position.
In the event of an activated spontaneous message,
the parameter channel is blocked until the sponta-
neous message has been acknowledged by the
master.
Example of a spontaneous message
Observation of the parameter channel (PCV) from the PPO (without index field):
PCV (Hex) PVA (Hex)
12 08 00 00 00 00
12 08 00 00 00 F0
12 08 00 00 00 00
AC 1A 00 00 00 0A
1C 08 00 00 00 00
1C 08 00 00 00 F0
The VLT saves up to 16 consecutively transmitted
SPMs in a FIFO buffer. If only one SPM is in the
FIFO buffer, the VLT immediately resumes normal
operations after the master has acknowledged it
(and the cause of the SPM has been eliminated). If
there is more than one SPM in the FIFO buffer, the
transmission takes place one after the other follo-
wing the acknowledgement. Additional SPMs that
are generated while the buffer is full will be
ignored.
16
VLT ® 5000/5000 Flux/6000 HVAC/8000 AQUA PROFIBUS
from from Description
Master VLT
x the master requests the current of the VLT
x VLT current value: 2.4 Amp (parameter 520)
x the master requests the current of the VLT
x VLT has a spontaneous message, the spontaneous message
bit is set, the PNU 538 (alarm word) has the value 000A (Hex)
x the master requests the current of the VLT and acknowledges
the spontaneous message by "toggling" the SPM in the PCV
x VLT current value: 2.4 Amp, the spontaneous message bit
remains at "1" until the next spontaneous message; the
spontaneous message is acknowledged.
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