JVL MIS17 Series, Руководство пользователя

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120 JVL Industri Elektronik A/S - User Manual - Integrated Stepper Motors MIS17x, 23x, 34x, 43x
5.7 SSI encoder/sensor interface
5.7.3 Setup and operation of the SSI function when NOT using MacTalk.
Following lines describe how to access relevant registers when having a SSI device con-
nected.
When reading the data from the SSI device the data will be places as a signed 32 bit inte-
ger in register 47 shortly after the read command have been executed.
The time before data is present can be calculated after following formula:
Total time from the read command 321 is executed until valid data is present is equal:
Time = Prepare time (timer) + (1/ Clock frequency * ( Number of Data bits +1))
Example:
Encoder used have following setup:
Prepare time = 100uS (0.0001 sec.)
Clock frequency = 10kHz (10000Hz)
Number of data bits = 25
0.0001+ (1/10000 * (25 + 1) = 0.0027 sec. = 2.7ms
Note:
If noise have affected the signal the time before valid data is presented will be longer.
Depending on the specific setting for the data validation function.
The position data from the encoder is presented in register 47 as shown below.
TT2482-01GB
31 30 29 28 27 26 25 24 23 22
Position data available as a signed 32 Bit integer
Register 47 - «EXTENCODER» (External encoder data) - Signed 32 bit integer.
21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
31
31
30
30
29
29
28
28
27
27
26
26
25
25
24
24
23
23
22
22
«Clock frequency»
(x 10kHz)
«Max. sample deviation»
(1-8191)
Not used / reserved
«Read
retries»
(2^n)
«Number of
databits»
«Prepare time»
(1µS * n)
TT2483-01GB
«Number
of
samples»
«Gray to
Bin converter»
Activator
(Set to 1" for Gray to bin
Set to for no conversion)
"
"0"
21
21
20
20
19
19
18
18
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
9
9
8
8
7
7
6
6
5
5
4
4
3
3
2
2
1
1
0
0
Register 107 - «SSI_SETUP1» - Unsigned 32 bit integer.
Register 111 - «SSI_SETUP2» - Unsigned 32 bit integer.