ifm electronic RM3001 - Handbuch (Seite 48)

48
Format of the scaling parameters:
DDLM_Set_Prm
Octet: 10 11 12 13
Bit 31 – 24 23 - 16 15 - 8 7 - 0
Data 2
31
- 2
24
2
23
- 2
16
2
15
- 2
8
2
7
- 2
0
measuring units per revolution
DDLM_Set_Prm
Octet: 14 15 16 17
Bit 31 – 24 23 - 16 15 - 8 7 - 0
Data 2
31
- 2
24
2
23
- 2
16
2
15
- 2
8
2
7
- 2
0
total measuring range in measuring units
The data type for both scaling parameters is 32 bits without sign, with a value range from 1 to 2 32 , which
is limited by the resolution of the encoder. For a 25-bit encoder with a singleturn resolution of 13 bits the
permissible value range for "Measuring units per revolution" is between 1 and 2
13 (8192) and for the
"Total measuring range in measuring units " the permissible value range is between 1 and 2 25 (33 554
432). The scaling parameters are securely stored in the Profibus-DP master and are reloaded into the
main memory of the encoder at each power-up.
Both parameters are entered in a 16-bit format, with a distinction being made between low word and high
word.
Example of scaling and entry:
Total measuring range in measuring units= 4.000 units x 3.200 revolutions
= 12.800.000
= 00 C3 50 00 hex
→
high word: 00C3 hex = 195
→
low word: 5000 hex = 20.480
Entry in the configuration software:
Total measuring range (units) hi = 195
Total measuring range (units) lo = 20.480
Note!
If the user wants to transmit a parameter telegram without changing the scaling parameters and with the
scaling function remaining enabled, the length of the telegram must be limited to 9 and the scaling
function control bit must be set. In this case the encoder only reacts on the parameter octets received.