Ramp Block

Purpose

The Ramp (RM) block decreases or increases a target output value. The block provides up to three stages for ramping values. Each ramp stage lets you specify a target value and a ramp rate. The first two stages also provide a hold time. At each scan cycle, the Ramp block sends its output value to the block specified in the Next Block field.

Features

The Ramp block:

• Is a primary block.
• Is a control block.
• Can be used as a stand-alone block.
• Can have a ramp rate manually changed in the iFIX WorkSpace through a Data link.
• Can have a target value manually changed in the iFIX WorkSpace through a Data link or by the Program block's SETTARG command.
• Can have a hold time manually changed in the iFIX WorkSpace through a Data link or by the Program block's SETTIME command.
• Can send its value to any secondary block.
• Operates in Automatic mode by initializing its current value based on the Low Limit value. On a transition to Automatic mode, the Ramp block begins the ramping process from where it last left off, using either the value it had reached when it was placed in Manual mode, or the latest values from the WorkSpace if the operator entered values while the block was in Manual mode.
• Operates in Manual mode by initializing its current value from either a manual entry or the Low Limit value. On a transition to Manual, iFIX suspends ramping until the block is returned to Automatic mode. The last current value of the block is output until the block is switched back to Automatic mode.

Typical Uses

Example

Fields