Configuration
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I-Am-Alive time
The parameter “I-Am-Alive time” serves for W-Master and W-Device
communication control if no other messages are transmitted. The W-Device
has to send an “I-Am-Alive” messages to the W-Master before timeout,
otherwise an error is reported, e.g. to start failsafe functionalities in the
application.
The “I-Am-Alive time” is a 16-bit value. Bits 7–0 contain the “Time base”
and bits 15–8 contain the “Multiplier”.
The “I-Am-Alive time” is calculated by multiplying the "Time base" with the
"Multiplier".
The following table shows the coding of the Time base.
Value
Time base
Description
0
Reserved
reserved, do not use
1
1.664 ms
Time base is 1.664 ms
2
5 ms
Time base is 10 ms
3
1 sec
Time base is 1 sec
4
1 min
Time base is 1 min
5 … 255
Reserved
reserved, do not use
Table 18: Time base of I-Am-Alive time
The Multiplier has the value range of 1 … 255.
The “I-Am-Alive time” is calculated by multiplying the "Time base" with the
"Multiplier", as shown in the following table:
Multiplier
(Bits 15-8)
Time base
(Bits 7–0)
Calculated
I-Am-Alive time
Value
1
1: 1.664 ms
1.664 ms
257
2: 5 ms
5 ms
258
3: 1 sec
1 sec
259
4: 1 min
1 min
260
2
1: 1.664 ms
3.328 ms
513
2: 5 ms
10 ms
514
3: 1 sec
2 sec
515
4: 1 min
2 min
516
3
1: 1.664 ms
4.992 ms
769
2: 5 ms
15 ms
770
3: 1 sec
3 sec
771
4: 1 min
3 min
772
4 … 254
1 … 4
Multiplier * Time base
Value of Multiplier * 256 + value of Time base
255
1: 1.664 ms
424.32 ms
65281
2: 5 ms
1275 ms
65282
3: 1 sec
255 s
65283
4: 1 min
255 min (10 min is used)
65284
Table 19: Calculation of I-Am-Alive time
NFD-3090-PNS-IOLM\W | Hardware, installation and commissioning
DOC201101UM03EN | Revision 3 | English | 2022-02 | Released | Public
© Hilscher 2020 - 2022
