Technical information

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Functions
Modicon M340 automation
platform
0
BMX EHC 0200/0800 counter modules
Operating modes for module BMX EHC 0200
8 configurable modes Frequency meter This mode measures a frequency, speed, data rate or an event stream.
As standard, this mode measures the frequency received on the IN A input.
This frequency is always expressed in Hz (number of pulses/second), with a precision of 1 Hz.
The maximum frequency on the IN A input is 60 kHz.
The maximum cyclic ratio at 60 kHz is 60%.
Event counting This mode is used to determine the number of events received.
In this mode, the counter calculates the number of pulses applied to the IN_A input at time
intervals defined by the user.
The module counts the pulses applied to the IN_A input each time the pulse for this input lasts
longer than 5 µs (without anti-bounce filter).
Period measurement This mode is used to:
Determine the duration of an event
Determine the time between 2 events
Time and measure the execution time of a process
It measures the time elapsed during an event or between 2 events (IN_A input) according to a
selectable time base of 1 µs, 100 µ
s or 1 ms.
The IN_SYNC input can be used to enable or stop a measurement.
The module can carry out a maximum of 1 measurement every 5 ms.
The shortest measurable pulse is 100 µs, even if the unit defined by the user is 1 µs.
The maximum measurable duration is 4,294,967,295 units (unit to be defined).
b
b
b
Ratio counting
Ratio counting mode only uses the IN_A and IN_B inputs. There are 2 possible modes:
Ratio 1: Used to divide 2 frequencies. This is intended for applications such as flowmeters,
mixers, etc.
Ratio 2: Used to subtract 2 frequencies. This is intended for the same applications, but for
those requiring more precise regulation (more similar frequencies).
Ratio 1 mode gives the results in thousandths for better accuracy (a display of 2000 corresponds
to a value of 2) and ratio 2 mode gives the results in Hz.
The maximum frequency that the module can measure on the IN_A and IN_B inputs is 60 kHz.
b
b
Downcounting
This mode is used to list a group of operations. In this mode, activating the synchronization
function starts the counter which, starting from a user-defined preset value, decreases with
each pulse applied to the IN_A input, until it reaches 0. This downcounting is made possible
when the enable function has been activated. The counting register is thus updated at 1 ms
intervals.
One basic use of this mode is to signal, using an output, the end of a group of operations (when
the counter reaches 0).
The shortest pulse applied to the IN_SYNC input is 100 μs.
The maximum frequency applied to the IN_SYNC input is 1 pulse every 5 ms.
The maximum user-defined preset value is 4,294,967,295.
The maximum count value is 4,294,967,295 units.
Loop (modulo) counting This mode is used in packaging and labelling applications where actions are repeated on sets
of moving objects:
In upcounting, the counter increases until it reaches the user-defined “modulo - 1” value. On
the next pulse, the counter is reset to 0 and upcounting restarts.
In downcounting, the counter decreases until it reaches 0. On the next pulse, the counter is
reset to the user-defined “modulo - 1” value. Downcounting can then restart.
The maximum frequency applied to the IN_A and IN_B inputs is 60 kHz.
The maximum frequency of the modulo event is 1 event every 5 ms.
The maximum modulo value is 4,294,967,296 (possible by declaring 0 in the
modulo adjust value).
b
b
32-bit counter counting
This mode is mainly used in axis following.
The maximum frequency applied simultaneously to the IN_A and IN_B inputs is 60 kHz.
The maximum frequency of the referencing event is 1 event every 5 ms.
The counter value is between - 2,147,483,648 and + 2,147,483,647.
Width modulation In this operating mode, the module uses an internal clock generator to supply a periodic signal
on the module's O0 output. Only the O0 output is affected by this mode, as the O1 output is
independent of it.
The maximum output frequency is 4 kHz.
As O0 is a source output, a load resistor is necessary for the O0 output signal to change to 0 at
the correct frequency.
The cyclic ratio adjustment range varies according to the frequency of the O0 output.
Processors:
page 1/2
Communication:
page 3/2
Software:
page 4/2
Ruggedized Modicon M340 modules:
page 6/2