Frequency measurement (FI = “Frequency Input”):
4 independent inputs for measurement of frequency and duty
cycle of periodic rectangular signals (max. 300 kHz). 4 further
channels can be added using the plug-on board ME-5002.
Pulse generator (FO = “Frequency Output”):
4 independent outputs for a periodic rectangular signal up to
3
kHz with a selectable duty cycle. 4 further channels can be
added using the plug-on board ME-5002.
The related pins are marked with FI_x and FO_x in the pinout pic-
ture on page 24. The remaining I/O-channels of the digital-ports
cannot be used in this configuration.
Note: For the configuration “pulse generator” (FO) take care of the
level at the unused pins DO_B4..15 (ME-5810) and DO_D4..15
(ME-5002). When used as sink drivers the channels are high im-
pedance, when used as source drivers they are connected to
ground!
The specifications of the digital-I/O ports also apply to the FI/FO
lines. A reference to the ground of the external circuitry via
GND_EXT (pins 9, 11, 59) has to be setup in any case.
The frequency counters and pulse generators are configured via
software. Chapter 4.1 on page 28 describes the programming of
the frequency-I/Os.
3.7 Counters
A standard counter chip of type 82C54 is used on the ME-5810
series boards. This versatile chip has 3 independent 16-bit (down-
ward) counters. All counter signals are available at the D-sub fe-
male connector.
With a suitable enabling of the GATE input (0 V) the related coun-
ter will start downward-counting with negative edge control. The
counter clock (CLK) has to be supplied externally and can be
max.10 MHz. With a suitable external wiring the counters also can
be cascaded.
All counter signals (CLK, GATE, and OUT) are opto-isolated. The
counter inputs have been designed for 24 V (R
v
= 3 k
Ω
) as used in
industrial control applications. When the counters are used, U
ext
