Hi All
Has anyone had issues running RTCM 3.MSM with a trimble base and rover? We're using Komatsu machine control (really Topcon) and rather then bumping down to CMR+ from CMRx I went the other way and changed over to RTCM. I did this to get more satellites for both machine control and rover (Topcon won't take cmrx). Everything worked pretty good for the first week but now I'm getting an extremely long "waiting for information from the base" message. I don't want to lose the extra satellite constellations that RTCM gives me. Also noticing quite a different base data age 3-5s, where cmr+ and cmrx are 1 second. Thanks and have a great day.
Regards
How many constellations? I was running into the same problem over UHF with three. I think it is a bandwidth thing. Also, have you checked that the modulation is working correctly? Test it out by broadcasting GPS only over CRM+.
CMRx is a LOT more compact than RTCM, so latency is definitely going to increase. It might even cause constellations to drop out of the solution because the receiver can't actually get the SV info in time to use it.
Topcon machines will accept RTCM 3.0, it will not work with RTCM3.3 MSM. We run CMR+ from our area base stations for the legacy topcon dozers. We are phasing out to all Trimble for machine control operations.
As mentioned by others its possible that too much data is trying to be pumped out of the radio. We often see 35 satellites now (all constellations) so it can be lots of data. The RTCM message format is great but its quite a bit bigger than CMR compact formats. Your radios will need to be configured for as high output as you can get so check your protocol settings and you may also need to turn off FEC because it adds overhead. Here is some good info from Mark Silver that is worth a read... Also carry a scanner, someone could be using the same frequency you are. I try to remember to carry mine with me every time I go to the field.
Best regards,
Terry
Search the web for “waiting for information from the base”. There are many posts about Trimble rovers waiting for specific RTCM messages from the base (eg base antenna specifics in message 1033) or that the 1033 message specifies an antenna that the Trimble rover doesn’t recognize.
