Experimental Physics and
Industrial Control System

"Pearson, Matthew R. via Tech-talk" <[email protected]> · Tue, 14 Jan 2020 22:57:19 +0000

Hi,

KRDG0 is indeed a device command, but I also embedded the device command strings into a lot of the record names, like:

record(ai, "$(P):KRDG$(INDEX)”)

where INDEX is 0-3 and D2-D5.

However, it may be reading zero if the polling is not enabled. There is an enable/disable polling record that is linked to the SDIS field of many of the input sensor related records. For example:

record(bo, "$(P):DISABLE_0”)

(and similar for inputs 1-3 and D2-D5). If these are 1 then the polling is disabled for the channel temperature, controller alarms, input descriptions and sensor configuration.

Set these to 0 to enable polling for the channels that you need. 

I think I added that feature originally for the Lakeshore 340 to deal with slow RS232 comms, but I’m not sure it’s an issue with the 336 and 350 controllers, so it’s probably fine to poll all the inputs all the time. However, the channel alarm logic is also tied into the DISABLE records, and typically unused channels will be in alarm state if there is nothing connected to them. So disabling polling is also a way to disable the alarm on unused channels. 

Cheers,
Matt

Data Acquisition and Controls Engineer
Spallation Neutron Source
Oak Ridge National Lab

> On Jan 14, 2020, at 5:36 PM, Goetze, Kurt via Tech-talk <[email protected]> wrote:
> 
> Hi Eliot,
>  
> I think you want to give caget an argument that is a PV name.  “KRDG0” looks like a device command.
>  
> Good luck,
> Kurt
>  
>  
> From: Tech-talk <[email protected]> On Behalf Of Specht, Eliot via Tech-talk
> Sent: Tuesday, January 14, 2020 4:10 PM
> To: [email protected]
> Subject: Lakeshore 336/360: how do I read the temperature
>  
> I’m trying to use Matt Pearson’s Lakeshore 336/360 IOC to interface a Lakeshore 336 temperature controller. The IOC seems to be running properly: I can read and write setpoints and PID parameters. But I’m having trouble figuring out how to read the temperature for the four sensors. It looks like
>                 caget KRDG0 (1,2,3)
> should work, but this returns zero for all four indices. I think that the IOC has provisions (which I haven’t been able to follow) for assigning different sensors to different channels; do I need to do some assignments before I can read temperatures?
>  
> I’m grateful for all the work which has gone into this IOC, and I would appreciate any help I can get in using it!
>  
> Eliot Specht

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System