FX30S DB9 serial port never sends or receives data from DCE

Nothing is ever sent or received on the DB9 serial port.

I followed manual instructions to enable serial for DB9 RS232

[code]root@fx30s:~# microcom -E /dev/ttyAT
!MAPUART: 17,0


root@fx30s:~# reboot
root@fx30s:~# ./rs485.py /sys/devices/platform/msm_serial_hsl.0/rs_mode 0
root@fx30s:~# ./rs485.py /sys/devices/platform/msm_serial_hsl.0/rs_mode
root@fx30s:~# reboot[/code]

Manual suggest using null modem adapter since i am try to talk to a DCE.
My adaptor uses two DB9 male connectors with the following wiring:

root@fx30s:~# microcom -s 115200 -E /dev/ttyHSL0 #1,N?;
The ASCII command #1,N?; should respond with a the device serial string from the DCE, which I have confirmed with other devices computers.

I have also tried the same instructions for UART2/ttyHSL1 but from what I can gather that is wired internally to the IoT board which I don’t have.

If I do a logread command, part of the boot message hints at a failure

Mar 2 01:24:49 fx30s user.info kernel: [ 1.139539] msm_serial: driver initialized Mar 2 01:24:49 fx30s user.info kernel: [ 1.139783] ttyHS0, function 0 is not valid on application processor. Mar 2 01:24:49 fx30s user.warn kernel: [ 1.139813] msm_serial_hs: probe of msm_serial_hs.0 failed with error -1 Mar 2 01:24:49 fx30s user.info kernel: [ 1.139966] msm_serial_hs module loaded

Please let me know if I missed a step or i am doing something wrong, or if the failure message indicates broken hardware.

Since this was asked for in a previous question here are the ATI and AT8 details

root@fx30s:~# microcom -E /dev/ttyAT
Manufacturer: Sierra Wireless, Incorporated
Model: FX30S
Revision: SWI9X15Y_07.11.22.00 r33729 CARMD-EV-FRMWR1 2017/01/11 18:04:06
MEID: 35398408007841
ESN: 12807114230, 806C8DF6
IMEI: 353984080078411
FSN: LL709600521610

Legato Ver: 16.10.1_eea67704afa1ebc0450d230baa84ac28
Yocto Ver: SWI9X15Y_07.11.21.00 2017-04-19_15:57:04
OS Ver: Linux version 3.14.29ltsi-a00e464379_c5f87a778d (jenkins@CAKEL-EV-ALBLD2) (gcc version 4.9.1 (GCC) ) #2 PREEMPT Wed Apr 19 15:36:04 PDT 2017
LK Ver: 1.3.0_b12d0630d0
RootFS Ver: SWI9X15Y_07.11.21.00 2017-04-19_15:57:04
UserFS Ver: unknown
MCU Ver: 001.011


From testing it would look like my null modem adaptor has the wrong wiring
Do you have a document somewhere that would show the right one

Hi there,
The kernel error that you noted is for the HS0 driver, not the HSL0 driver, so it doesn’t apply.

As a test, without the NULL modem cable, could you try setting MAPUART=16,1 and see if you’re getting console messages to your computer?


Yes that works, but that is with a straight though cable.
So my question remains am I using the correct null modem wiring? I’ve seen at least 4 types

I think i may have found something.
The User Guide PDF says

However the recent firmware update guide says

So which is it.

The device I am attaching needs/uses Hardware flow control, so is this the source of my problems?

The correct Null Modem adapter for my particular Hardware flow control device is:
Loopback handshaking

Hi there,
I apologize, but 8 wire UART with hardware flow control is currently not supported.