CONV-TTL-RTM-RS485 PTS documentation

PTS system

Unlike the rest of the PTS systems, that for the CONV-TTL-RTM-RS485 is for now not designed for sending to the assembly facility. Instead, we will be testing the boards right here at CERN once they arrive upon shipment.

The test system is really simple. It comprises the following components:

CONV-TTL-RTM-RS485 under test
CONV-TTL-RS485 with dedicated PTS gateware
two RS-485 tester cards, described in the hardware guide
dedicated Python scripts

Tests

Number	Name	Description
test01	LEDs	Light each rear panel LED in sequence and ask the user whether they light up
test02	Pulse repetition	Send pulses on all channels from all outputs in sequence and check that they are received at the input

Setting up

You should follow these steps to set up a CONV-TTL-RTM-RS485 PTS system. Note that the steps are performed under Ubuntu Linux.

Obtain an ELMA crate and set it up to be accessible from the network (write down the IP)
Set up the ELMA crate as shown in Section 4 of the setup guide
Clone the PTS repository
Prepare some Lemo 00 cables from the front to the back of the crate as described in Section 2 of the setup guide (abstracting away the 19'' rack part)
Set up the PTS system for the ELMA crate as described in the Appendix of the setup guide
Plug a CONV-TTL-RS485 in the front part of the ELMA crate
Connect a JTAG cable to the CONV-TTL-RS485
Get a USB key and format it as pts

Running

# Run the pts.py script in the folder structure (conv-ttl-rs485-tst/pts-rtm/ubuntu/t485-rtm)

%> ./pts.py
Hello and Welcome to the CONV-TTL-RTM-RS485 PTS!

# Scan or type the 1st and second barcodes

--> Scan the 1st barcode: 1234
--> Scan the 2nd barcode: 1234

--> Plug the CONV-TTL-RTM-RS485 board '1234-1234' into the VME crate.

Connect two RS485 testers to the RTM under test, one between CH1-3 and one between CH4-6
Now, plug the RTM board under test in the rear part of the ELMA crate and type "ok"
A new xterm window will open up, informing you on the results
When testing is finished, the xterm window will close and the output file will be copied to the USB stick
In case of errors, they will be output to the console
Unplug the card, disconnect the RS485 testers and place the RTM in its box

Debugging

LED errors should be pretty straightforward to debug, since you see which LED doesn't work.

Should errors appear on the RS485 pulse test, first swap the RS485 testers between them and try again, they might not be properly connected (they're pretty hard to plug in).

If the errors persist, run the test again. If it fails with the same errors, check the output channels which are erroneous. Should it be all input channels, check those.

Getting the files

* Clone the repository:

git clone git:https://www.ohwr.org/level-conversion/conv-ttl-rs485/conv-ttl-rs485-tst.git
cd conv-ttl-rs485-tst/pts-rtm

Theodor-Adrian Stana, Jan. 2015

Rtm