RL (Rate Limiter) - Metasys - LIT-12011964 - Software Application - System Configuration Tool - 13.2

Metasys SCT: System Configuration Tool Help

Brand
Metasys
Product name
System Configuration Tool
Document type
User Guide
Document number
LIT-12011964
Version
13.2
Revision date
2020-01-21
Language
English

The Rate Limiter block controls the rate at which its Output changes with variations in its Input value. If rate limiting is disabled, this block passes the value of the Input to the Output. If rate limiting is enabled, this block limits changes to its Output to an increment determined by the Step Equation, executed according to the rate limit. This table describes the components of the Rate Limiter block:

Table 1. RL (Rate Limiter Blocks)

Symbol

Description

IN

Input

EN

Enabled

Enables rate limiting. Use a binary object attribute reference for EN:

0 = Disabled (Inactive command)

1 = Enabled (Active command)

Rate Limiter blocks use the Step Equation to determine the maximum increment (step) the Output can change to match the Input if the two differ. The Step Equation recalculates the step every time system logic executes (every 5 seconds).

The Step Equation looks like this:

Step = Rate Limit/60,000 * Actual Period

Where:

Rate Limit:

Rate per minute to increase or decrease the Output until it matches the Input

Actual Period:

Time in milliseconds since the last execution of the block. The system logic and Step Equation execute every 5 seconds (5,000 milliseconds).

For example, if the Rate Limiter block is set up like this:

Rate Limit = 10

Actual Period = 5,000 (milliseconds)

The Step Equation looks like this:

Step = 10/60,000 * 5,000

Step = 0.8

So, the maximum increment the Output can change on its way to match the Input is 0.8.

See Editing Blocks in Edit Mode for information on editing Rate Limiter blocks.