An update: I was able to obtain the complete Spirent GSS4200 Utilities disk/installer ... it seems to have everything required (scenarios, USB drivers, etc.).
I haven't had a chance to play with them yet. If anyone is in a similar position to me and in need of this disk, let me know ... --Andrew On Sat, Apr 24, 2021 at 1:19 AM Andrew Kalman <[email protected]> wrote: > So, an update. I was graciously provided with the User Manual for the > GSS4200 (thank you!). Having read through it and having played with my > GSS4200, I conclude the following: > > - My unit is functionally working (well) -- 10MHz clock was not far > off, output levels are correct, etc., it is generating a signal where one > should be. > - Most of the "commanded" behavior I had been observing (using the > GSS6100 user manual as a guide, issuing commands over GPIB) was the > behavior of the unit when operating in GSS6100 emulation mode (single > channel, ability to change the SVID, maybe the ability to change the week, > etc.). > - This GSS4200 has (sadly) only one scenario loaded in its NVM memory > -- "4200calibration" that is 10 minutes long. It basically outputs a > single-channel signal on PRN 1, makes sense for calibration. > - Based on my reading of the manual, at a minimum, if you have access > to the utilities CD ROM, you can load scenario "libraries" (#sats, signal > strengths, ground trajectories, etc.) and then run them (in a looping mode, > if you want) on this unit. A combination of utilities (that work only over > USB) load scenarios into the GSS4200. > - Each scenario also includes the appropriate ephemeris and almanac > info (provided by Spirent). > - Scenarios must be under 5 minutes long.Dunno how the 4200calibration > scenario is 600s long ... > - The scenario and other file formats are not / not well documented. > Spirent had a server that you would provide scenario requests to, and I'm > guessing that it would generate the scenario file along with the > accompanying ephemeris and almanac info, and crunch that all into a .scb > scenario file. You can then use a provided utility to combine multiple > scenarios into a scenario library that you can then load into the GSS4200. > Note that there is no obvious way for a user to ** generate ** their own > scenarios (or ephemeris or almanac). > - GSS6100 emulation is "independent" of GSS4200 scenario operation. > For example, the GSS4200 manual does not mention an explicit level command > (that is part of the GSS6100's command set), yet the example scenarios > alter the output level, so clearly the unit can do that. > - So, the intended way to use this unit appears to be: > - Obtain supplied/default scenarios (*.scb) or ones built for you > via the Spirent web interface > - Optionally combine them into libraries (*.scl) via the Scenario > Selection Tool > - Download them into the GSS4200 (max 512KB worth) using the Flash > Loader Utility > - Run the scenario via RUNS <x> for one run, or LOOP <x> for > looping, where <x> is the scenario number. > > > - So, I'm kinda stuck here. I want the GSS4200 available for a quick > and consistent validation of the proper operation of GPS receivers. For > that, at a minimum, I need some complete scenarios (the default ones > supplied with the unit would be alright) that I can load into the unit to > run in looping mode. There are 18 default scenarios, 3 each (different > power levels, stationary vs. moving, etc.) for six cities: Boston, LA, > Tokyo, Hanover, Seoul and Shanghai.They all run at various dates in 2003, > suggesting that the GSS4200 was released around that time. > - My unit only has the one calibration scenario (PRN 1 only, standard > output level) loaded ... I'm not really clear on the usefulness of a single > channel of GPS signal. > - This unit differs from more modern units like Spectracom/Orolia GSG > series units in that the newer units allow you to generate your own > scenarios, and they pull ephemeris and almanac data directly from the > internet. Plus more channels and constellations, more interference and > other simulations, etc. > > So, I conclude that without the full GSS4200 utilities disk, I'm kinda > stuck. :-( > > --Andrew > > -------------------------------- > Andrew E. Kalman, Ph.D. > > > On Fri, Apr 23, 2021 at 1:15 PM Andrew Kalman <[email protected]> wrote: > >> Hello. >> >> [SNIP] >> >> I am ** desperate ** for a User Manual for the Spirent GSS4200 GNSS >> simulator (e.g., >> https://www.testequipmentconnection.com/54837/Spirent_GSS4200.php). That >> model is somewhat unique, in that it's one of only a very few that Spirent >> released that can/will run without an external "control" program. Using the >> manual from the GSS6100, I'm able to do a couple of things with the GSS4200 >> over GPIB, but for the life of me I cannot figure out how to get the >> GSS4200 into a mode other than single-channel (it supports 6 channels, and >> has a single-channel mode). I suspect there is a command to do this, but I >> have not been able to figure it out. >> >> I have spent 8+ hours searching sites and archives, to no avail. Spirent >> has done a rather impressive job of locking down their support software and >> docs behind a paywall (and I wonder if they even have the docs for the >> GSS4200 any more). Any help is appreciated, I'm happy to give back if >> someone wants to snag another GSS4200 (around $700 used) and use it as a >> simulator. >> >> _______________________________________________ time-nuts mailing list -- [email protected] -- To unsubscribe send an email to [email protected] To unsubscribe, go to and follow the instructions there.
