SCI1 communication problem

[kneedown]

I am configuring an IsoPodX to send data to a Rogue Robotics uMMC SD board and am having trouble getting them to "talk" to each other via the SCI1 RS232. I can communicate between the IsoPodX and my PC using SCI1 and I can communicate between my PC and the uMMC board using its TTL via a Maxim 233 CPP but when I link the pod's SCI1 to the Maxim chip input (via a standard nine pin socket) I cannot get any communication. I've connected thus (the uMMC uses 9600 Baud):

IsoPodX DB9 socket Function
Pin 7 of J2 ------> Pin 3 sin1
Pin 9 of J2 ------> Pin 2 sout1
Pin 5 of J2 ------> Pin 5 Gnd

When the uMMC receives a carriage return, it should return ">". I've tried this using the following:

DECIMAL 9600 SCI1 BAUD
DECIMAL HERE 35 ALLOT CONSTANT BUFFER1
BUFFER1 35 SCI1 RXBUFFER
DECIMAL HERE 50 ALLOT CONSTANT BUFFER2
BUFFER2 50 SCI1 TXBUFFER
HEX 0D SCI1 TX

then

SCI1 RX? . (to see if there is anything waiting in the receive buffer, this returns "0")

I've also used the code given in the manual to "listen to" SCI1.

I'd be grateful for any help and ideas to solve the problem. I should add that I am a beginner with IsoMax so maybe I'm doing something wrong with the code?

[nmitech]

I can communicate between the IsoPodX and my PC using SCI1 and I can communicate between my PC and the uMMC board using its TTL via a Maxim 233 CPP but when I link the pod's SCI1 to the Maxim chip input (via a standard nine pin socket) I cannot get any communication. I've connected thus (the uMMC uses 9600 Baud):

IsoPodX DB9 socket Function
Pin 7 of J2 ------> Pin 3 sin1
Pin 9 of J2 ------> Pin 2 sout1
Pin 5 of J2 ------> Pin 5 Gnd


I think you need to swap wires either on pin 2 & 3 of uMMC, or pin 7 & 9 of IsoPodX

[kneedown]

Thanks for your quick response - I tried swopping wires and still no change.

Edit - apologies, just tried connecting the output from IsoPodX pin 7 to pin 9 so that what was sent immediately went to the receive and it worked fine. Reconnected the wires as you suggested and now have communication between the two boards - thanks for your help.