Experimental Physics and
Industrial Control System

Michael:

We've been using the DTM-151's with stream device support successfully. I am glad to hear that we are not the only ones to encounter problems with the proprietary network scheme, which we implemented initially using fibre for three devices. After fighting with the system for many months, I concluded that the protocol implementation in the DTM-151 is faulty.
Since connecting each to a dedicated serial port on our IOC, they have been problem free. Our implementation is pretty much identical to Stephanie's. We included support for range selection and RESET, which is also quite simple. Ask me if you need example code.

Rod Nussbaumer
TRIUMF,
Vancouver, Canada.

On 03/30/2015 01:25 PM, Allison, Stephanie wrote:

Hi Michael,

We have integrated the DTM-151 teslameter ... somewhat.  We found it best to connect each one directly to the terminal server.  These teslameters are not so tolerant of radiation.  We only got 2 out of 5 working properly (the other 3 were in higher radiation places).

The proto file:

# Stream device protocol file for Group3 Hall Probe

   # Harvey Rarback
   # July 31, 2009

WriteTimeout = 10000;
ReadTimeout  = 10000;
ReplyTimeout = 10000;

ExtraInput    = Ignore;
OutTerminator = "";
InTerminator  = CR;

field {
   out "F\r"; # send request
#  in "A%*i";     # fiber interface echo
   in "%f";      # device returns field
}

temp {
   out "T\r"; # send request
#  in "A%*i";     # fiber interface echo
   in "%f";      # device returns temperature
}

The database:

record(ai, "$(DEV):MagField") {
   field(DESC, "Hall Probe field")
   field(DTYP, "stream")
   field(INP,  "@hallprobe.proto field $(PORT)")
   field(SCAN, "$(FIELD_SCAN_RATE)")
   field(EGU,  "T")
   field(PREC, "5")
   field(MDEL, "$(MDEL)")
   field(PINI, "YES")
}

record(ai, "$(DEV):MagTemp") {
   field(DESC, "Hall Probe temperature")
   field(DTYP, "stream")
   field(INP,  "@hallprobe.proto temp $(PORT)")
   field(SCAN, "$(TEMP_SCAN_RATE)")
   field(EGU,  "C")
   field(PREC, "1")
   field(PINI, "YES")
}

I have some notes from Harvey Rarback who has since retired:

Teslameter Jumper, Dip Switch, and Rotary Switch Settings:

Refer to the user manual, and use defaults for option and handshake jumper pins. If the teslameter is connected directly to the terminal server or PC serial port, set T/M pins to terminal mode. If teslameter is connected to the DPM display, set them to modem mode (default). Set rotary switch to "E" (9600 baud). Set S1-1 to S1-5 to the device address. To choose 8 data bits, no parity, and 1 stop bit, set S1-6 to On, S1-7 to Off, and S1-8 to On. Set S2-1 to Off (on-demand transmission), S2-2 to S2-4 to On (select terminator = carriage return, double terminator = enabled, echo = On), and S2-5 to S2-8 to Off (units = tesla, no units symbol, no filtering, defaults = no action).
DPM Teslameter Display Instructions
Change the address of the DPM with the two cryptically labeled front panel switches, ROLL (R) and SELECT (S). When the address is changed, the display shows the corresponding teslameter output and ignores all other addresses.
To change the address:

     Hold R down and press and release S and then release R
     Do this again
     Press S to increment the address, maximum 31
     Press R to decrement the address, minimum 0
     Do step 1 again to return to field display

Stephanie Allison

-----Original Message-----
From: [email protected] [mailto:tech-talk-bounces@aps.anl.gov] On Behalf
Of Michael Davidsaver
Sent: Monday, March 30, 2015 12:30 PM
To: [email protected]
Subject: support for DTM-151?

Has anyone integrated a Digital Teslameter 151 from Group3?

http://www.group3technology.com/index.php/products/product/digital-teslameter-151