SurvCE v1.67 & Allegro CX: Command Shell?
I recently bought a Leica TCRA1102plus with an Allegro CX running SurvCE v1.67 from a colleague. I knew that robotic communications weren’t working when I bought it, and the repair estimate came in at around $1,200 to replace one of the RFM radios and associated bits. I decided to convert the system to bluetooth communications, since I already had a receiving unit that I use with a Geodimeter 640 and DC50. (Unfortunately, the DC50 can’t seem to talk reliably with the Leica, so I have to use the Allegro with it.) The second bluetooth radio cost less than $150, so I’d save a fair bit of money over replacing the RFM radio.
The combination worked fine during testing. I would first open a terminal window, issue the appropriate AT command to COM1 to pair the bluetooth radios, then close the terminal window, launch SurvCE, and I’d be in business.
Then I decided to fit the bluetooth radio inside the Allegro rather than hanging it off the COM1 connector on top. This provides two advantages: better physical protection for the radio (which sticks out a couple of inches from the comm port, not counting the antenna), and the ability to draw power from pin 4 of the com port, thus saving me the trouble of having to maintain a separate battery for the radio.
Unfortunately, when I close the terminal window pin 4 goes to zero or negative, which turns off the bluetooth radio, thus losing communication with the radio at the gun. (The SurvCE manual made me aware that pin 4 can, under certain circumstances allowed by RS232, go to -5v, so I put a diode in line with the radio for protection.) This wasn’t an issue when I had the radio running off it’s own battery, but now I need to either find another place to get +5v inside the Allegro (unlikely — it’s tight in there!), find a way to send an AT command string to COM1 while running Carlson (what I’m hoping for), or take power from the Allegro charge connector on top and route another cable into the radio pod.
Thanks for any insight or suggestions!
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