FXT0020 Expansion Card - Incomplete Documentation

This is an expansion card for the Fastrack Xtend, etc. that provides:

  • RS485 interface
  • 6 isolated digital inputs

The manual for this card is WA_DEV_EC0020_PTS_001" Rev 001 January 21, 2011.

I realise that this card wasn’t designed by Sierra Wireless but the documentation for both the expansion card and the Fastrack Xtend modem is incomplete! :frowning:

In particular, the manual shows the correspondence between each isolated input line available on the card’s I/O connector to the card’s 50-pin connector, but where is the mapping from the 50-pin connector on the Fastrack Xtend motherboard to the embedded Q2687 module’s 100-pin connector??

Maybe I’m missing something but I can’t see that information in the manual for the Fastrack Xtend modem? :astonished:
Fastrack Xtend User Guide WA_DEV_FEX20_UGD_002 Rev 004 March 08, 2011

It would be real handy to know what GPIO pins the four isolated digital inputs are actually mapped to in hardware Its a bit hard to actually make use of them otherwise!

Also, the INTO interrupt pin is used on this card. Looking at the block diagram is appears to be a interrupt-on-change facility for the isolated inputs. Does the circuit block generate an interrupt on all both rising and falling edge changes on any input or just one edge?

More candidates for documentation augmentation/improvement by Sierra Wireless!! :wink:

OK, as an addendum to the last post, in the absence of documentation I have had to expend some effort :frowning:
ferreting around the remaining documentation, specifically the manual for the other expansion card, the “GPS + I/O Card”:
FXTE01 and FXTE02 User Guide WA_DEV_FEX20_UGD_008 Rev 001 July 02, 2010

I have deduced the connections from the 50-Pin expansion connector on the motherboard of the Fastrack Xtend modem to the 100-pin Interface connector of the Q2687 module. To assist others who might want to use expansion cards, I have appended several columns to the information contained in table7 of the Q2687 Product Technical Specification and Customer Design Guideline and attached a document here.

For the EC0020 RS485 Expansion Card the isolated inputs and other control lines appear to be mapped as follows:

Card | Expansion Connector
Signal | Pin# Signal Name (for Q2687)

INPUT_4 | 19 SPI2-CLK / GPIO32
INPUT_3 | 20 SPI2-IO / GPIO33
INPUT_2 | 21 SPI2-CS / GPIO35
INPUT_1 | 22 SPI2-I / GPIO34

Fastrack Xtend Modem Motherboard Connectors - Pin Assignments.pdf (46.4 KB)