Mode 3 Request for Memory Mapped I/O Address

[84Elky]

'7730 $8d using TPro RT v5 - Is it possible to make a Mode 3 request to read a memory mapped i/o address (eg. 1-byte 0x4008); and if so, how would it be entered in the transmit string? "0x40 0x08" does not work as it does if it was a memory address. Is a different format required for addresses between 0x3000 and 0x6FFF? Thanks!

[VL400]

On our aussie PCMs you can get everything using mode 2 requests for 64 byte blocks. Mode 3 we dont use very often due to it being only 1 byte of data returned but that still works for any address too.

Mode 2 Frame To Send: F4 58 02 00 00 CS
This requests a 64 block starting from address 0000. The CS is checksum and can be calc'd in TunerPro

[84Elky]

On our aussie PCMs you can get everything using mode 2 requests for 64 byte blocks. Mode 3 we dont use very often due to it being only 1 byte of data returned but that still works for any address too.

Mode 2 Frame To Send: F4 58 02 00 00 CS
This requests a 64 block starting from address 0000. The CS is checksum and can be calc'd in TunerPro

Thanks! Will try that tomorrow. BTW, can get up to 6 bytes for sure and maybe 8 with Mode 3 and requests can be selective addresses, not in a 64 byte sequence. Am using that successfully, but for some reason when try to get 0x4008, TPro barfs and get no data at all.

[VL400]

Yeah should have been more clear. The mode 3 on ours operates the same with up to 6 address' being requested per mode 3 frame with each returning 1 byte from that address. Its very useful if you want certain things spread throughout memory Its just got a fair bit of overhead.

For faster logging can mod a spare mode 1 message to include only the items your wanting (this is what we do in 12P using custom mode 1 message 6 frames). It can be requested faster using just F4 57 1 X CS (X being the mode 1 message you modded). The size can also configurable.

[84Elky]

Thanks! Yes, there is certainly some overhead with Mode 3. Have done some sample frequency tests (results here [Post #12]: http://www.gearhead-efi.com/Fuel-Inject ... DL-Command). Would be interesteed in what sample frequency you are seeing in various modes.

Not sure I understand the Mode 1 modification you referenced. Will not a Mode 1 request always transmit the # of bytes specified in the code mask (63 for my AUJP $8d)? And then to get a byte that is not predefined in those 63 bytes, an address needs to changed in the mask with a hex editor to reflect the requested byte. Seems you are describing something I'm not familiar with.

Any chance you could provide an example of Mode 1 requesting, say only 0x4008, and having only that byte transmitted. Thanks again.

BTW-Will play with Mode 2 once can get data for 0x4008.