Experimental Physics and
Industrial Control System

Alan Greer <[email protected]> · Tue, 26 Mar 2013 15:22:58 +0000

Hi, I have a question regarding motor record precision that I would like

clarified.

Setup

OS - Debian 6
EPICS base - R3.14.12.3
ASYN - R4.18
MOTOR - R6.7.1

I have sub-classed asynMotorController.cpp and when I read the position

of an axis I use the following lines to store the position values.

position and enc_position are both doubles.

setDoubleParam(pC_->motorPosition_, position);
setDoubleParam(pC_->motorEncoderPosition_, enc_position);

In the motor record instance the .RBV value appears to come back as an

integer, despite placing a double value into a double param.

eg.

Actual position = 106.501000390592
.RRBV = 106
.RBV = 106

Could someone give me some advice on setting up the precision that

doesn't involve me scaling the value up and then setting .MRES and .ERES?

Does .PREC do what I want?
Or have I missed something else?

Any help appreciated.

Kind regards, Alan Greer

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System