In a conversation this morning with MTH R&D, we discussed a technical issue that has lately been a topic of conversation on the forum. The subject was regarding updating sound files in DCS engines. I asked if I could get a better understanding of the issue and the reasons behind it. thsi thread is intended to pass what I learned along to any of you who may be interested.
Several forum members have reported receiving advice from MTH that, when transferring sound files via the DCS Loader Program, certain techniques should be utilized so as to decrease the occurrence of errors and to reduce the time necessary for the transfer. The two techniques are:
- Use DC voltage for track power as opposed to AC voltage
- Ensure that at least 20 feet of wire is between the TIU channel output and the track upon which the target DCS engine resides.
However, there are two caveats that are sometimes not stated:
- These are only applicable when the TIU is a Rev. L and the engine is a PS3
- If DC voltage is used, the 20 feet of wire is not necessary.
Further, the reason for these techniques also are often not mentioned.
The Rev. L TIU was designed to be more effective on larger layouts than previous TIUs. It's equipped with an FPGA (Field-programmable gate array) chip for its digital sound processor (DSP) as opposed to the ASIC (application-specific integrated circuit) used in earlier TIUs. The FPGA allows the Rev. L TIU to communicate more effectively with all DCS engines than could previous TIUs.
Further, PS3 engines also have FPGA chips instead of the ASIC chips that are in PS2 engines (both 5 volt and 3 volt varieties). The combination of both Rev. L TIUs and PS3 engines having FPGA chips is what allows for improved communications between the Rev. L TIU and PS3 engines, which also leads to improved PS3 engine signal strength.
However, one drawback of this scenario is that at times complex communication with a PS3 engine (such as what occurs during a sound fike transfer) may actually degrade because the TIU is "shouting" at the engine and the engine is "shouting" back. The two things that can correct this "shouting" match are to either quiet any electrical background noise by using DC voltage rather than AC voltage, or by separating the TIU from the engine with 20 feet of wire. Either one should suffice to eliminate the problem.
Again, this scenario can only occur when using a Rev.L TIU to transfer sound files with a PS3 engine.
As an experiment, I intend to try something I never would have attempted before. That is, transferring a sound file between a PS3 engine and the PC, while the engine is on the layout. If someone beats me to it, please post your results on this thread. I'll do the same.
