Principles of Operation
99
Measure Counter Features
DT9857 and DT9857E modules provide two measure counters (counters 1 and 2). Using these
counters, you can measure the frequency, period, or pulse width of a single signal or the time
period between two signals and return the value in the analog input stream. This is useful for
correlating the analog input data with digital positional data, measuring the frequency of a
signal, or as a tachometer. An internal 48 MHz counter is used for the measurement, yielding a
resolution of 20 ns (1/48 MHz).
To use measure counter 1, specify channel 10 for the DT9857-08 and DT9857E-08 module, or
channel 18 for the DT9857-16 or DT9857E-16 module in the analog input channel list. To use
measure counter 2, specify channel 11 for the DT9857-08 or DT9857E-08 module, or channel 19
for the DT9857-16 or DT9857E-16 module in the analog input channel list.
Using software commands, you can configure the following parameters for counter 1 and/or
counter 2:
• The operation mode as continuous edge-to-edge measurement mode.
• The signal that starts the measurement. The following signals are supported:
−
A/D conversion complete
−
Tachometer input falling edge
−
Tachometer input rising edge
−
Digital input 0 falling edge
−
Digital input 0 rising edge
−
Digital input 1 falling edge
−
Digital input 1 rising edge
−
Digital input 2 falling edge
−
Digital input 2 rising edge
−
Digital input 3 falling edge
−
Digital input 3 rising edge
−
Digital input 4 falling edge
−
Digital input 4 rising edge
−
Digital input 5 falling edge
−
Digital input 5 rising edge
−
Digital input 6 falling edge
−
Digital input 6 rising edge
−
Digital input 7 falling edge
−
Digital input 7 rising edge
−
C/T 0 Clock input falling edge
−
C/T 0 Clock input rising edge
−
C/T 0 Gate input falling edge
Содержание Data Translation DT9857
Страница 1: ...DT9857 and DT9857E UM 25656 M User s Manual Title Page ...
Страница 4: ......
Страница 10: ...Contents 10 ...
Страница 14: ...About this Manual 14 ...
Страница 15: ...15 1 Overview Hardware Features 16 Supported Software 19 Supported Accessories 22 Getting Started Procedure 24 ...
Страница 25: ...Part 1 Getting Started ...
Страница 26: ......
Страница 40: ...Chapter 2 40 ...
Страница 61: ...61 4 Verifying the Operation of a Module Select the Device 63 Acquire Data from an Analog Output Channel 65 ...
Страница 64: ...Chapter 4 64 ...
Страница 71: ...Part 2 Using Your Module ...
Страница 72: ......
Страница 126: ...Chapter 6 126 ...
Страница 127: ...127 7 Troubleshooting General Checklist 128 Technical Support 130 If Your Module Needs Factory Service 131 ...
Страница 132: ...Chapter 7 132 ...
Страница 140: ...Chapter 8 140 ...
Страница 180: ...Appendix B 180 ...
Страница 181: ...181 C Register Level Programming Writing to the EEPROM Register 182 ...
Страница 184: ...Appendix C 184 ...
Страница 192: ...Index ...