Calling Topcon PS users! Difficulty acquiring lock to prism
I have a Topcon PS-101A robotic total station. Sometimes I use the instrument in typical 1-man robotic mode with RC-PR5 controller mounted on prism pole, and on other jobs, I use it in more conventional 2-man setup, with me on the data collector at the instrument and my partner at the prism pole (without the RC-PR5). I’ve typically been using Carlson SurvCE 6.06, but also have a license of Topcon Magnet Field.
I’m having a very hard time acquiring lock prior to a shot, and the difficulty appears to be related to whether the prism is fixed or moving at the time. I believe the problem exists whether I’m using in robot or 2-man conventional modes, though I notice it more in the latter mode because I am at the instrument. The problem is especially frustrating on a shot where the prism cant be held fixed, say locating a fence behind a thick bush and having to “boot” the prism pole up over the bush. This is physically strenuous, and it is important to be able to acquire lock quickly, take the shot, and call out “good” to the rod man so he knows he can bring the pole down. Another tough situation might be taking a shot to a peanut prism where the rod man is on the ground, again in a strenuous position, and not able to hold the prism perfectly still for long. Add to that the simultaneous stress of bugs, etc. and it is nearly impossible.
I’ve made two short videos that illustrate the problem. The first video (<3 min) shows the problem generally:
https://www.youtube.com/watch?v=hFQONeCXTFs
A second video (<1 min) shows the behavior of instrument as viewed through scope.
https://www.youtube.com/watch?v=bNFhhP3_W0M
I’ve been communicating with Carlson about this, thinking that the problem has something to do with Carlson’s software. However, after some recent testing, I’ve seen that the problem exists using SurvCE but also when using Topcon’s Magnet Field. So, I’m thinking the problem may fall in one of three categories:
- There is some fault in the Bluetooth communication which causes slow or interrupted data transfer (I doubt it)
- There is a user configurable setting in the instrument that isn’t set optimally (I hope so)
- The problem is not user configurable, and reflects a limitation of the instrument itself (Please I hope not)
One work-around I have found is to turn the instrument to the backsight prism in between shots, ideally before it initiates the search, fails, and goes into standby. If I can maintain lock on the backsight prism up until the moment when the rod-man is ready with the next topo shot, then I can quickly turn from the backsight prism to the prism pole, and it will quickly acquire lock the moment the prism comes into the field of view of the telescope.
Years ago, I used a Sokkia SRX3 with a TDS Ranger data collector running Spectra Precision Survey Pro. This instrument setup, despite being many years older, worked great for topo – the gun quickly acquired lock any time the prism came into the field of view of the telescope. It didn’t initiate a search pattern, it didn’t go into standby mode, and was always ready to acquire lock. Really fast. In my mind the newer instrument should be even faster at this than the older instrument, yet in practice is it far worse.
I would appreciate any suggestions on this problem, especially from Topcon PS users.
Thanks,
Al
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