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Local functions user manual
EX1608DD module
update: 16-06-2017
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Table of contents
1. Module requirements .............................................................................................................. 3
1.1. The local functions ....................................................................................................................... 3
1.2. Functions area of EX1608DD module ........................................................................................... 3
2. Counting functions .................................................................................................................. 5
2.1. Function 1: up counting on rise edge ........................................................................................... 5
2.2. Function 2: down counting on rise edge ...................................................................................... 5
2.3. Function 3: up counting on fall edge (from r.01.008 / P03452) .................................................... 6
2.4. Function 4: down counting on fall edge (from r.01.008 / P03452) ............................................... 6
3. Impulse capture functions ....................................................................................................... 7
3.1. Function 10: rise and fall edge capture (from r.01.008 / P03452) ................................................ 7
4. Frequency measure functions .................................................................................................. 8
4.1. Function 100: frequency measure on 1” interval ......................................................................... 8
4.2. Function 101: frequency measure on 10” interval ....................................................................... 8
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1. Module requirements
The functions described in this manual have been introduced with the firmware release “r.01.005”.
So verify, with the “Test module” function of “Modbus-Tool” utility, that in the module is installed
this firmware or a later release. Alternatively the device serial number with the final field greater or
equal to “N05376” insures that the new firmware is installed.
However, since new features can be added at a later time, check the minimum version of the
firmware as described in the documentation of the specific function.
1.1. The local functions
The I/O slave modules make available to the master PLC their specific resources using words of
only input type and holding registers that are generally words with read and write access. Normally
the holding registers are associated to output resources, but are also used for the configuration
resources of the module. In addition to this, a memory area, of holding register type, has been
defined for the management of a series of “special functions” of the module. These functions are
defined as local because the operations are executed by software running locally on the module
itself, alleviating the master PLC from the management of tasks that can weigh down on its cycle
time and particulary overload the bus communication.
1.2. Functions area of EX1608DD module
The EX1608DD slave module offers, for this purpose, an area of 500 holding registers starting at
address 1000. In particular 16 areas, size of 10 words each, are assigned respectively to the 16
digital inputs of the module. The first word of each area (offset +0) is used to enable and configure
the function associated with a specific input . The 0 value disables the function and values greater
than 0 enable different functions. The word with offset from +1 to +9 are used for the management
of the particular function and their meaning changes according to the function code configured in
the word +0:
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Holding Register
Descri
ption
1000 Function configuration of
input channel
00
1001 First data word used by the function of input channel
00
-------
1009 Last data word used by the function of input channel 00
1010 Function configuration of input
channel 0
1 1011 First data word used by the function of input channel
01
-------
1019 Last data word used by the function of input channel
01
------- 1150 Function configuration of input channel
15 1151 First data word used by the function of input
channel
15
-------
1159 Last data word used by the function of input channel
15
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2. Counting functions
Codes 1 through 9 are dedicated to the enabling of counting functions. The EX1608DD module is a
generic digital I/O module and is not dedicated to the particular tasks that require high reading
speed as in the case of encoder in positioning systems. The module can instead be used for
counting of pulses whose frequency do not exceed 1KHz with square waveform type.
NOTE: The module does not provide the backup of counters in permanent memory so, each time
the device is powered, the counters contain the value 0.
2.1. Function 1: up counting on rise edge
The code 1 enables count function with an increase of one unit every rising power of the
corresponding input. The count word is available for reading and writing at the address with offset
+1 with refer to the area dedicated to the channel. When the counter reaches the value 65535, it
restarts from counting value 0. To reset or preset the counter the same holding register can be
over-written:
Holding Register
Read
/
Write
Descri
ption
+0 = 1
R / W Enable of u
p counting
+1 = val
ue R / W Current value of counter
2.2. Function 2: down counting on rise edge
The code 2 enables count function with a decrease of one unit every rising power of the
corresponding input. The count word is available for reading and writing at the address with offset
+1 with refer to the area dedicated to the channel. When the counter reaches the value 0, it
restarts from counting value 65535. To reset or preset the counter the same holding register can
be over-written:
Holding Register
Read
/
Write
Descri
ption
+0 = 2
R / W Enable down
counting
+1 = val
ue R
/ W Current value of counter
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2.3. Function 3: up counting on fall edge (from r.01.008 / P03452)
The code 3 enables count function with an increase of one unit every falling power of the
corresponding input. The count word is available for reading and writing at the address with offset
+1 with refer to the area dedicated to the channel. When the counter reaches the value 65535, it
restarts from counting value 0. To reset or preset the counter the same holding register can be
over-written:
Holding Register
Read/Write
Description
+0 = 3
R / W Enable of up counting
+1 = value
R / W Current value of counter
2.4. Function 4: down counting on fall edge (from r.01.008 / P03452)
The code 4 enables count function with a decrease of one unit every falling power of the
corresponding input. The count word is available for reading and writing at the address with offset
+1 with refer to the area dedicated to the channel. When the counter reaches the value 0, it
restarts from counting value 65535. To reset or preset the counter the same holding register can
be over-written:
Holding Register
Read/Write
Description
+0 = 4
R / W Enable down counting
+1 = value
R / W Current value of counter
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3. Impulse capture functions
Codes 10 through 19 are dedicated to the enabling of impulse capture functions. The EX1608DD
module can store the detection of short-duration signals which can be lost in the case of I/O
update at lower frequencies. The input of module must remain in a defined logic state for a
minimum of 0.5ms so that it can be recognized the related signal.
NOTE: The module does not provide the backup of the detected values in permanent memory so,
each time the device is powered, the reading returns the value 0.
3.1. Function 10: rise and fall edge capture (from r.01.008 / P03452)
The code 10 enables capture function for the rising and falling edge of the power applied to the
related input. A word is available for reading and writing at the address with offset +1 with refer to
the area dedicated to the channel. The bit 0 of the word is forced to 1 by the module when it
detects a rising edge, while the bit 1 is activated to 1 when a falling edge is detected. The word can
be cleared by writing the holding register. However, for ease of management, the module
automatically provides to clear the word after its reading:
Holding Register
Read
/
Write
Description
+0 = 10
R / W Enable edges capture
+1 = value
R / W BIT 0:
rise edge detected
, BIT 1:
fall edge detected
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4. Frequency measure functions
Codes 100 through 109 are dedicated to the enabling of frequency measure functions. The
maximum frequencies that the EX1608DD module can measure do not exceed 1KHz with square
waveform type.
4.1. Function 100: frequency measure on 1” interval
The code 100 enables the function of frequency measure for the signal applied to the digital input
channel. For every rising power of input, an internal counter is incremented by one. An internal
clock, at regular intervals of 1 second, samples the current counting, updates the measured value
in the holding register and then resets the counter for the next reading:
Holding Register
Read
/
Write
Descri
ption
+0 = 1
00 R / W F
requency measure on
1” interval
+1 = val
ue R Current value of frequency (
units
1Hz)
4.2. Function 101: frequency measure on 10” interval
The code 101 enables the function of frequency measure for the signal applied to the digital input
channel. For every rising power of input, an internal counter is incremented by one. An internal
clock, at regular intervals of 10 seconds, samples the current counting, updates the measured
value in the holding register and then resets the counter for the next reading:
Holding Register
Read
/
Write
Descri
ption
+0 = 101
R / W F
requency measure on 1
0
” interval
+1 = val
ue R Current value of frequency (
units 0.
1Hz)
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