Analog Output Setup
The 9125 controller has the option of six analog outputs. The outputs are ranged for a 4 – 20 milliamp signal or a 0 – 20 milliamp signal. Each output comes with a factory default configuration dependent on the application. Each output can be modified prior to shipment to your facility or in the field by a supervisor.
Analog Output Terminals
Analog output 1 – terminals 24 and 25
Analog output 2 – terminals 25 and 26
Analog outputs 3, 4, 5, and 6 are enabled by use of an SSi QuadDAC board that connects to two RS485 terminals on the 9125 (terminals 5 and 6 for client 1, terminals 22 and 23 for client 2). Use the Port Setup menu to configure communication parameters.
Assignment
The analog output assignment can be modified depending on your system requirements. To change the Assignment first select which analog output you want to change by selecting it in the pull-down menu just below the main menu. Clicking on this value will display an input box, and then you can use the pull-down menu to select the desired parameter. Once selected, click OK and the displayed assignment under Value will be the current assignment type. The following is a list of the options:
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PV 1 retrans Loop 1 inc Loop 1 dec Loop 1 combo PV 2 retrans Loop 2 inc Loop 2 dec Loop 3 combo PV 3 retrans Loop 3 inc Loop 3 dec Loop 3 combo Input 1 retrans Input 2 retrans Input 3 retrans |
Not assigned O2 offset log SP1 retrans SP2 retrans SP3 retrans Valve 1 SP Valve 2 SP Valve 3 SP Valve 4 SP Disabled
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Combo example for carbon: 4 – 12 mA Air
12 – 20 mA Gas
Offset
This is the starting point, the Process Variable value at which you get 4 milliamps if the output is set up as 4-20mA (or 0 milliamps if output is set up as 0-20mA). Clicking on this value will display an input box from which the user can select a new value. The range is –32768 to 32767.
Range
This is a Process Variable value between 4 and 20 milliamps (or 0 and 20 milliamps, depending on setup). . Clicking on this value will display an input box from which the user can select a new value. The range is –32768 to 32767.
Note - The range, although not displayed with a decimal point, contains a decimal point that is dependent on the process variable selected. For example, if the offset is 20 mV for 4 mA, and you want 100 mV to be 20 mA, then your range should be 80. If the process variable is temperature, then the range will be 80, since temperature PVs do not have a decimal. If the PV is % Carbon, then the range will need to include the two decimal points for % Carbon. So, a range of 80 will be entered as 8000. See below for more examples.
Current Selection
Provides the option of 4-20 mA or 0-20 mA control. Clicking on this value will display an input box with a drop-down list from which the user can select either of the two values listed above.
Offset and Range when assigned to a control loop
Inc : 0 = 4mA, 100 = 20mA
Dec : 0 = 4mA, -100 = 20mA
Example: if 4 – 20 mA = 800 mV - 1200 mV
Offset = 800 (starting point)
Range = 400