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Programming and Operating Concepts
Video Recorder – User Manual 52
Function block parameter
A function block parameter’s data is contained within the block. When you are programming a function
block and are not given a choice of PARM, you are programming a function block parameter. Typical
choices when programming a function block parameter are NONE, OFF, any numerical value, or a list of
options for the parameter, but not PARM. See Figure 3-7.
For example, to program an Alarm function block’s ALARM ACTION, you select from a list of choices:
NONE, LOW, HIGH, DEV, LRATE, HRATE.
Other function block parameters are an Analog Input’s RANGE LOW and RANGE HIGH, where you
specify the voltage range or temperature range.
Output code
An output code is the result of the function block's operations on the input parameters and function block
parameters. It is designated by one of the two-character output codes shown in Table 3-4. An output
code can be programmed to be the input to one or several other function blocks. See Figure 3-7.
Output codes are either discrete (can be on or off) or analog (numerical value). For example, DI1 OS is
the output status of Discrete Input #1: on or off. AI1 OV is the output value of Analog Input #1: a voltage
or temperature. Therefore, a discrete input parameter must be programmed with only a discrete output
code, and an analog input parameter must be programmed with only an analog output code.
ATTENTION
The function block SYSTEM PARAMETER, abbreviated SY, does not have input parameters or function block
parameters like the other function blocks; SY produces output codes only. These output codes, shown in Table
3-4, are mostly values or states that indicate the status of system-wide parameters. For example, if any Alarm
function block’s output status is ON, the SY function block’s AG (alarm global) output code is also ON.
Another example is the SY F1 output code, which produces a quick ON-to-OFF discrete signal when the F1
key is pressed. This SY F1 can be used as a trigger to another action. For example, to allow an operator to
start the Profile or reset the Totalizer by pressing the F1 key, you can program a Setpoint Profile’s Start
parameter or a Totalizer’s Reset parameter with SY F1.