Hach-Lange SC 1000 - Manual (Page 74)

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Standard Operations
5.15 Formula editor for output and relay card
Formulas can be used as additional signal source for output and relay cards (DIN rail and
expansion cards). Each channel of the output or relay card can be used to run a formula.
The result of a formula can be used the same way like real measured values.
By using formulas, “virtual measurements” can be created (for example average values
from measured values of multiple probes). The virtual measured value is calculated from
the measured readings of other probes.
5.15.1 Add a formula
To add a formula:
1. Select sc1000 SETUP,
a. for an output card continue with OUTPUT SETUP, mA OUTPUT INT/EXT,
OUTPUT 1-4, SELECT SOURCE, SET FORMULA.
b. for a relay card continue with RELAY, RELAY INT/EXT, RELAY 1-4, SENSOR,
SET FORMULA.
2. The main menu of the formula editor is displayed ( Figure 50 ). Tap on the text fields to
edit the Name, Location, Unit, Parameter and Formula.
Common examples for formulas are “LOAD” or “DELTA-pH” ( Table 23 ):
Figure 50 Main menu of the formula editor
Table 22 Formula settings
Function Description
Name
Enter a reference name for identification in display views and log files (Maximum of 16
characters).
Location Enter an additional location information for unique identification (Maximum of 16 characters)
Unit Enter a virtual measurement unit (Maximum of 6 characters).
Parameter Enter a virtual measurement parameter (Maximum of 6 characters).
Formula
Enter a formula, which calculates the virtual measurement value. The formula can use
letters A, B, C as shortcuts for other measurement values (
Table 24 , Table 25 , Table 26 ).
Definition for letters A, B, C Lists the existing assignments (for other measurement values).
Add (Tag) Creates a new letter (A, B, C) as a place holder for another new measurement value.