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Emax

Index last updated: 2026-04-28 23:23 UTC

Message

Re: EMUSER and Emax I

2011-04-19 by Adam

First of all, thank you for caring!

i had the idea, that on the MAX'es the +/- things should be swapped.
but why on the SN?

In the meantime i've ordered the original ICs you used from the US, because i could see these nowhere around. I'll definietly going to compare these part by part, and will let you know if we found out something!

thanks,

adam

--- In emax@yahoogroups.com, "esynthesist" <esynthesist@...> wrote:
>
> I just did a quick comparison of the ICs you used with the ones as specified for the EmuSer. At first sight they should be compatible, although yours are a bit slower...
> 
> However when checking your connections mentioned in your message below, I think you have swapped the inverting and non-inverting pins.
> I think the RXD+/RXD- and TXD+/TXD- must be swapped on the MAX and SN ICs...
> 
> ///E-Synthesist
> 
> --- In emax@yahoogroups.com, "Adam" <fake@> wrote:
> >
> > well, it starts to make sense! it really looked disappointing, now there are new things to check. 
> > 
> > meanwhile i switched to an Emulator II+HD to do the tests, because i know that works well with SD thru DB25. is it fair to assume that it has a healthy port and will work with the EMXP too?
> > 
> > i put this back to the bench and will check if there were any signals coming in and out on the TX-RX stuff. i havent included the LEDs on this design.
> > 
> > since the UA9637AC is not available around, i replaced it. i did not use any capacitors and resistors though. i assume you used it to shape the signal (apart from those to support the LEDs). if there were any other reasons, please let me know, i need to check that.
> > 
> > i am going to list the short description of my version in a very easy way. everything is connected direct, no resistors or capacitors used. please see below if you were interested in.
> > 
> > "So, what error do you actually get in EMXP ?   "
> > 
> > When receiving from the EII it says: Errorcode 990. There is a communication problem with the EII. ReasonCode is 3.
> > 
> > i am going to post it quick, so maybe you had more time to check and think, and now i'll return to measure the circuitry.
> > 
> > and now the connections:
> > 
> > 
> > 
> > RECEIVER (RX): MAX RS485
> > ---------------------
> > TXD+ (Emax: pin8) -> Teensy RXD+ (RS422:3) -> RS485:7 (B)
> > TXD- (Emax:pin9) -> Teensy RXD- (RS422:4) -> RS485:6 (A)
> > GND (Emax:pin3) -> Teensy (RS422:5) -> RS485:5 (GND) 
> > RS485:pin1 (R0) -> Teensy PD2 (RXD1)
> > RS485:pin2 (NRE) -> L 
> > RS485:pin3 (D) -> L  
> > RS485:pin4 (DI) ->  not connected 
> > 
> > TRANSCIVER (TX): MAX RS485
> > ------------------------
> > Teensy TXD (PD3) -> RS485:pin4 (DI)
> > RS485:pin6 (A) -> Emax:pin5 (RXD-)
> > RS485:pin7 (B) -> Emax:pin4 (RXD+)
> > RS485:1 (R0) -> not connected
> > RS485:2 (NRE) ->H
> > RS485:3 (DE) ->H
> > 
> > CLOCK (CLK): SN75176B
> > ------------------------
> > CLK (Emax:5) -> SN75176B Pin6 (A) 
> > SN75176B:pin7: B -> L
> > SN75176B:pin1: R -> Teensy PD5  (XCK)
> > SN75176B:pin4 (D) -> not connected
> > SN75176B:pin3 (DE) -> L 
> > SN75176B:pin2 (NRE) -> L
> >
>

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