Condition-Controlled Frequency Measurement; Fig. 6-5: Possibilities For Parameter And Condition At The Gate Input - Bosch Rextroth Indramat RECO R-IB IL CNT Applications Manual

6-4
Commands used when working with the Counter Terminal

Condition-Controlled Frequency Measurement

High level
Low level
Rising edge
Falling edge
If it is important to have a short reaction time then a lower gate time
should be used; this in turn results in an unfavorable resolution.
A simple processing of the counter value may also be required within an
application. At a resolution of 1 Hz/LSB, the counter value does not have
to be converted into the frequency.
In the condition-controlled frequency measurement, the parameter
indicates the condition of the gate input in which a count is made or in
which the counter value is accepted.
Parameter
(dec) (code and parameter)
1020
1021
1022
1023

Fig. 6-5: Possibilities for parameter and condition at the gate input

In this measurement, the count is made during the time in which there is a
high level at the gate. The counter stops on the transition to low level. The
last counter value is accepted in the input data.
The count is re-started at 0 at the next high level.
In this measurement, the count is made during the time in which there is a
low level at the gate. The counter stops on the transition to high level. The
last counter value is accepted in the input data.
The count is re-started at 0 at the next low level.
In this measurement, the count begins immediately on transmission of the
command for frequency measurement. The current counter value is
accepted into the input data at every rising edge of the gate signal. The
counter is reset to 0 and the count is continued.
In this measurement, the count begins immediately on transmission of the
command for frequency measurement. The current counter value is
accepted into the input data at every falling edge of the gate signal. The
counter is reset to 0 and the count is continued.
Note: If the condition for counting is already at the gate on
transmitting the command (e.g. a high level at 13FC
the first count begins immediately. This count cycle may have
to be discarded according tot he application used as the entire
duration of the gate signal is not detected.
Control word (hex)
13FC
13FD
13FE
13FF
DOK-CONTRL-R-IL*CNT***-AW02-EN-P
Counter Terminal
Count or acceptance of
the counter value at
High level
Low level
Rising edge
Falling edge
) then
hex