Objectives Upon completion of this module you will be able to:
Define the purpose of the Multifunction Card
Define the screw terminals used on the terminal block
Define the input frequencies for both sine and square waves
Define the user parameters on a pulse input channel
Define the pulse input function block parameters used
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Multifunction Card & Terminal Block Power
LEDs:
Error
Green - On powered and self tests are good. Red ON - Failed and/or not communicating to the controller. Red Flashing - Card not being scanned by controller Multi-function card supports four channels configured as Discrete Inputs (DI) or Pulse Inputs (PI). Multi-function terminal block has 32 terminals available. The matrix below shows the terminals used with current release capabilities for the card and the terminal connections for use with future enhancements.
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Multifunction Terminal Block Matrix Position 1
Position 2
Position 3
Position 4
Position 5
Position 6
Position 7
Position 8
Top Row
1 AI-Ch 1
5 AI-Ch2
9 AI-Ch3
13 AI-Ch4
17 (+) DI-Ch1
21 (+) DI-CH2
25 (+) DI-Ch3
29 (+) DI-Ch4
Second Row
2 AI-RTN
6 AI-RTN
10 AI-RTN
14 AI-RTN
18 (-) DI-RTN
22 (-) DI-RTN
26 (-) DI-RTN
30 (-) DI-RTN
Third Row
3 AO-Ch1
7 AO-Ch2
11 +24VDC
15 +24VDC
19 (+) DO-Ch1
23 (+) DO-Ch2
27 (+) DO-Ch3
31 (+) DO-Ch4
Bottom Row
4 AO-RTN
8 AO-RTN
12 24V-RTN
16 24V-RTN
20 DO-RTN
24 D0-RTN
28 DO-RTN
32 DO-RTN
Reserved for future use Currently being used
The Multifunction Card was designed to support high frequency pulse input.
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Pulse Input Specifications INPUTS
Input frequency — sine wave 10Hz - 50KHz, Square Wave 0.1Hz - 50KHz
Isolation — Each channel is optically isolated from the system at 250 VAC
Resolution counter — 32 bits
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17-7
Multifunction Card Channels
17-8
Multifunction Card Channels Using DeltaV Explorer
The Multifunction Card has four channels used as Discrete Inputs or as Pulse Inputs. The Multifunction Card is specifically designed for high frequency pulse inputs. The Channel properties dialog box includes:
Enable: A check in this box enables the port to be the channel on the Multifunction card. Description: Up to 40 characters for a description to appear in Explorer Channel Type: The user chooses between Discrete Input and Pulse Input. Device Tag: The user may enter a unique name, up to 16 characters, for each channel. The example above shows Pulse-1.
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Multifunction Card Channels
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Multifunction Card Channels Using DeltaV Explorer
The Pulse Input Channel parameters include:
Counter_In: Usable in control strategies as an external reference Raw Count. Reset_Count: Usable in control strategies as an external reference. Writing a non-zero number to this parameter clears the Counter_In parameter. Channel Type: The user chooses between Discrete Input and Pulse Input. Device Tag: A unique name, up to 16 characters, for each channel. The example above shows Pulse-1. Frequency: Only valid I/O_In parameter to a pulse input function block, also usable in control strategies as an external reference. 17-11
Multifunction Card Channels
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Multifunction Card Channels Using DeltaV Explorer
The Pulse Input channels provide a count and frequency. The signal frequency is calculated from the number of pulses received over a configured scan period. You can define the scan period with the FILTER parameter. In selecting the right filter for the application, you must determine what emphasis should be placed on precision and what should be placed on response, particularly for slower frequencies (below 250Hz). The default filter is 1 second.
Filter Parameter: Selecting FILTER Parameter Properties opens the FILTER Properties box. A drop-down window titled Named Set provides you with the predefined filter values that can be used.
As the filters increase, the scan time increases. As the filters decrease, so does the scan time. Larger filters will give you more precision, but the longer scan rate will decrease the response to the frequency changes.
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Pulse Input Function Block
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Pulse Input Function Block Using DeltaV Control Studio
Drag ‘n drop a Pulse Input function block from the I/O category of the function block palette. Example: A turbine meter used to measure volumetric flow of a gas steam. The pulse input function block measuring volumetric flow of a natural gas stream. Pulse Input function block parameters:
I/O_In — Use the browser to select the DST for this input Out_Scale — 0 to X, the range of the meter, used only to back calculate the Field_Val parameter in percent
Because the meter is pre-set to measure a specific unit, you are permitted to designate
PULSE_VAL — Converts the frequency from the card, from pulses to EU in the calculation of PV TIME_UNITS — The lapsed time over which a single pulse’s units are counted 17-15
Summary
What is the purpose of the Multifunction Card? What screw terminals are used for the Pulse Input device connections? What is the input frequency for a sine wave input? Name two parameter of the Pulse input channel that may be used as external references. When using a Multifunction Card pulse input channel, what is the only valid parameter for I/O_IN to the Pulse Input function block?
