Manual ME-582x Series
Revision 0.9
3 Hardware
page 16
Meilhaus Electronic
the application). At full load this means minimum 6 A for the ME-582x. The
output voltage U
Out,H
can be calculated like this:
U
out, H
= U
ext
– (R
ON
⋅
I
out
)
3.5
Frequency Input/Output
With the concept of “configurable subdevices” on the ME-5000 series
boards you can use certain subdevices with an alternative functionality.
The configuration tool ME-iDC is used to change the configuration before
the user application is started.
The following channels are available:
Frequency measurement
(FI = “Frequency Input”):
ME-5820 has 4, ME-5821 has 8 independent inputs for measurement
of frequency and duty cycle of periodic rectangular signals (max.
300 kHz).
Pulse
generator (FO = “Frequency Output”):
ME-5820 has 4, ME-5821 has 8 independent outputs for a periodic
rectangular signal up to 3
kHz with a selectable duty cycle.
The related pins are marked with FI_x and FO_x in the pinout picture 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-5820) and DO_D4..15 (ME-5821). When
used as sink drivers the channels are high impedance, 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 22 describes the programming of the frequency-I/Os.
3.6
Counters
A standard counter chip of type 82C54 is emulated used on the ME-582x
boards. This versatile chip has 3 independent 16-bit (downward) counters.
All counter signals are available at the D-sub female connector.
With a suitable enabling of the GATE input (0 V) the related counter will
start downward-counting with negative edge control. The counter clock
