Elmo HARmonica, HARSFEN0602 software manual 160, External position reference generator

ElmoHARSFEN0602HARmonicaSoftwareManual PRELIMINARYDRAFT

160

PTP or PVT. The position of the conveyer is not known in advance, and it must be measured on line, for example by using the auxiliary encoder input. The reading of the auxiliary input is scaled by the follower ratio (FR[3]) parameter, and added to the software command.

Driving the amplifier as a slave in a larger arrangement. For example, when the amplifier moves valve in a pressure control system, its position command may be

•an analog output of a pressure controller.

Synchronizing several amplifiers. Several amplifiers may be driven by an auxiliary encoder signal. Each of the amplifiers uses its ECAM table to derive its own motion path from the auxiliary signal.

The external position reference is generated by the following scheme:

Analog input 1

`

(-10 to 10 Volts)

-

AS[1]

Σ

Auxiliary encoder

input

AG[3]

Count/Volt

Σ

FR[3]

ECAM table

Use ECAM

if EM[1]==1

Auxiliary position

command

		Figure 30: External position reference generator
The following parameters determine how the position reference is composed:
	Parameter	Action
	AG[3]	Scale the analog input. The units of AG[3] are counts/Volt.
	AS[1]	Offset the analog input. The units of AS[1] are Volts.
	FR[3]	Scale the auxiliary encoder input. FR[3] is applicable only if the auxiliary encoder is
		not used for position feedback.
	EM[1]	Define if the ECAM table transforms the external reference or not.
		EM[1]=0: Do not use ECAM table
		EM[1]=1: Use ECAM table for transforming the external command.
	RM	Define if an external reference is used at all
		RM=0: Don’t use external reference
		RM=1: Use external reference