JX2-CNT1
12 Frequency Measurement
Jetter AG
77
12
Frequency Measurement
Frequency measurements are carried out by means of the count value in register
3xx0. This measurement is always carried out in the background. The frequency
value can be read out at any time. The frequency value is used for calculating the
speed (RPM). The frequency measurement is carried out for both the dual-channel
counter (incremental encoder), and the SSI encoder.
The frequency value indicates the number of increments captured during a time
interval (time between 2 measurements). The duration of the time interval is set by
means of the time base value (see formula below).
The frequency value is displayed in register 3xx7 "Frequency - Display" and the time
base is set in register 3xx1 "Frequency - Time base". Both registers have got a
double function: Register 3xx7 is used to read or write the SSI parity error counter
and register 3xx1 is used to read or write the dual-channel offset. The function of
these two registers is set by means of bit 12 in register 3xx3 "Status / Controller":
The frequency value is calculated as follows:
Count value
n
is captured later by the value of register 3xx1 x 10 ms than count value
n-1
.
Bit 12 = 0:
Register 3xx7:
Counter of SSI parity errors
Register 3xx1:
Dual-channel counter - offset
Bit 12 = 1:
Register 3xx7:
Frequency - display
Register 3xx1:
Frequency - time base
Status bit 12 = 1
Register 3xx7: Frequency - Display
Function
Description
Read
Present frequency value (for dual-channel counter
or SSI encoder)
Write
Illegal
Value range
- 8,388,608 ... + 8,388,607 [increments / time
interval]
Value following reset
0
Register 3xx7
Count
n
Count
n 1
–
–
Register 3xx1 10 ms
×
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Содержание JetWeb JX2-CNT1
Страница 10: ...Table of Contents JetWeb 10 Jetter AG ...
Страница 18: ...1 Safety Instructions JetWeb 18 Jetter AG ...
Страница 26: ...JetWeb 26 Jetter AG ...
Страница 58: ...8 2 Firmware Version JetWeb 58 Jetter AG ...
Страница 60: ...JetWeb 60 Jetter AG ...
Страница 63: ...JX2 CNT1 10 Dual Channel Counter Jetter AG 63 Fig 13 Signal waveform for single channel counting ...
Страница 74: ...11 1 Reading in SSI data JetWeb 74 Jetter AG Fig 18 Examples Reading in Different SSI Formats ...
Страница 82: ...12 1 Sample Program JetWeb 80 Jetter AG ...
Страница 90: ...13 2 Mode 2 Operation along with JM 2xx JetWeb 94 Jetter AG ...
Страница 91: ...JX2 CNT1 Appendices Jetter AG 95 Appendix ...
Страница 92: ...Appendices JetWeb 96 Jetter AG ...
Страница 95: ...JX2 CNT1 Appendices Jetter AG 99 ...
Страница 99: ...JX2 CNT1 Appendices Jetter AG 103 ...