Emerson E2 operation manual Setting Up Digital Inputs

sensor value are entered in the Select Eng. Units field. This value is set automatically to an appropri- ate default unit whenever the Sensor Type is changed. To select a different engineering unit, press

or to scroll through the options or select the unit from the  (LOOK-UP).

Units Per Pulse The Units Per Pulse field appears only when “Pulse Accum” is entered in the Sensor Type field.

The E2 is capable of generating an analog KW value by counting the number of pulses from the pulse accumulation outputs of a KW transducer. Each pulse from the transducer signifies that a fixed num- ber of KW has been used.

The number of KWs per pulse varies depending upon the type of transducer being used. Consult the trans- ducer’s documentation for the exact number of KWs per pulse and enter it in this field.

Default on Open The value placed here will deter- mine the value the unit reports if there is an “open” condition detected in the sensor input connection. An “open” condition could be the result of a broken wire to the sensor or a sensor failure.

Default on Short The numeric entry in this param- eter is the default value the analog input would report if a “short” is detected on the sensor input connec- tion. A “short” could be the result of a damaged wire or a sensor failure.

Default Other The value placed in Default Other is the value reported if the input is not updated after a certain amount of time. If there is a failure that will not allow the input board to report the value of the sensor, the value placed in this parameter will be reported.

Sensor Offset If a sensor needs a numeric value

added or subtracted to the calculated value, enter the number here. The value can be positive or negative. Sensors sometimes have to have offsets. The offset that you enter in this field is in the units you selected in the Eng Units field, NOT in millivolts.

Output This field displays the link between the input and the application(s) they feed into. You do not need to enter anything in this field. You will be able to link applications to this point during the application setup process.

9.1.3.4Setting Up Digital Inputs

Open the Digital Input screen by selecting a Digital (D) input from the Input Status screen Figure 9-4and pressing  (SETUP).

Set up digital inputs in order to assign digital input

points, point names, engineering units, and other impor- tant parameters.

Figure 9-7- Digital Input Screen

Point Name The Point Name is simply a name for the point that may be used as a reference.

Assigning a descriptive name to a point makes set- ting up inputs for applications much easier. For example, if you are setting up a push-button switch to reset compressor 1 after an oil failure shut down, you may choose to name it “OIL RESET 1”. Then, when programming your Pressure Control applica- tion, you may easily define compressor 1’s reset input by tying it to OIL RESET 1. This keeps you from having to keep track of which contacts are tied to which point numbers.

You are required to enter a point name in the Point Name field. The default name is “:{BOARD NAME}:{BOARD NUMBER}:{POINT NUM- BER}.”

Board/Point Number The Board/Point Number will automatically be defined if you are configuring the point from the Input Summary Screen.

Select Eng. Units The Select Eng. Units field is where you may select how the ON and OFF states of this point are displayed and represented in E2’s setup fields and status screens. By default, digital inputs have ON-OFF engineering units, meaning when the input is ON or OFF, the input will be represented as “ON” or “OFF” in the system software.

Since the controller looks at only the actual state of the point when it uses the input for control purposes, it is not necessary to define engineering units for dig- ital inputs. However, selecting units that are appro- priate to the input’s function (such as BYP or

The 16AI, 8IO, and MultiFlex Inputs Input and Output Setup • 9-9