please try the latest beta MP
help > update beta
@Michael_Oborne
Thank you for answering.
I did load the beta verion before attempting to look at the RFD 900X. (See result in screen grab below)
Just for info: Using hyper terminal can talk to this modem and the AT command works fine.
Kind regards
Henri
can you run all the at command in hyperterminal and post a picture of the answers?
please try the latest beta.
its been updated again
Hi Michael.
By the way I did try to change some parameters on the RFD 900X, such as S3 that I did set to 65 and stored the value with AT&W. Then rebooted the modem and value was correct.
So it definitely shows this modem to be alive.
Here is AT command and answers from the old hyperterminal:
OK
ATI
RFD SiK 2.53 on RFD900xR1.1
ATI2
131
ATI3
0X0091
ATI4
255
ATI5
S0:FORMAT=32
S1:SERIAL_SPEED=57
S2:AIR_SPEED=64
S3:NETID=65
S4:TXPOWER=30
S5:ECC=0
S6:MAVLINK=1
S7:OPPRESEND=0
S8:MIN_FREQ=915000
S9:MAX_FREQ=928000
S10:NUM_CHANNELS=20
S11:DUTY_CYCLE=100
S12:LBT_RSSI=0
S13:RTSCTS=0
S14:MAX_WINDOW=131
S15:ENCRYPTION_LEVEL=0
S16:GPI1_1R/CIN=0
S17:GPO1_1R/COUT=0
R0:TARGET_RSSI=255
R1:HYSTERESIS_RSSI=50
ATI6
silence_period: 252
tx_window_width: 6354
max_data_packet_length: 249
packet_latency: 126
ATI7
L/R RSSI: 0/0 L/R noise: 79/0 pkts: 0 txe=0 rxe=0 stx=0 srx=0 ecc=0/0 temp=28
dco=0
ATS0?
32
ATS1?
57
ATS2?
64
ATS3?
65
ATS4?
30
ATS5?
0
ATS6?
1
ATS7?
0
ATS8?
915000
ATS9?
928000
ATS10?
20
ATS11?
100
ATS12?
0
ATS13?
0
ATS14?
131
ATS15?
0
ATS16?
0
ATS17?
0
ATS18?
ERROR
With “Beta updated” version of Mission planner, it does connect to the modem. 
Thank you Michael. below is a screen grab of the successful connection.
I’ll try to connect to the airframe when daylight shows and will try CPPM as well. Will measure latency on CPPM with a scope.
Kind regards
Henri
Very great timing!
I started testing 2 RFD900x yesterday and ran into the same issue
I will try the Beta of MP and check back.
Mine just arrived today!
Will be using PPM Passthrough feature…IF I can figure out how and which pin to use.
Anyone can provide a shortcut?
If you look at the setup screen, I would think depending if you set GPI1R/C in or out the CPPM function would be enable.
This is, however, a question for Seppo at rfdesign…
Henri
just for those that don’t realize it
GPI1_1 = R/C In or R/C Out
I am attempting to use the RFD900x to passthrough PWM or PPM…
From other discussions it seems that “GPI1_1 = R/C In or R/C Out” refers to RFD900x GPIO Pin 15 (or P2.6). Is that correct? I was trying to use PIN 13 (of P0.1)…
Some clarification on the setup would be great.
I am assuming that I setup
GPI1_1R/CIN checked at the transmitter end of the link and
GPI1_1R/COUT checked at the other end of the link.
Do I need to setup the radio with AT commands to make the pins at the transmitter end Inputs or is the PPM function separate from these settings?
RTPP
put Val: 0
Pin:1 Output Val: 0
Pin:2 Output Val: 0
Pin:3 Output Val: 0
Pin:4 Output Val: 0
Pin:5 Output Val: 0
ATPP
Pin:0 Output Val: 0
Pin:1 Output Val: 0
Pin:2 Output Val: 0
Pin:3 Output Val: 0
Pin:4 Output Val: 0
Pin:5 Input Val: 1
ATPI=4
OK
ATPP
Pin:0 Output Val: 0
Pin:1 Output Val: 0
Pin:2 Output Val: 0
Pin:3 Output Val: 0
Pin:4 Input Val: 1
Pin:5 Input Val: 1
RTZ
Thanks for a prompt reply - the project is getting urgent.
Michael Nunan
Will you use CPPM capabilities of the RFD900X as well?
Great found this thread !
Any one know how to connect the Rc Transmitter ?
Someone said use pin15 for signal cable. How about the rest ? 5v and Ground ?
If you look at the RFdesign provided documentation you’ll see:
Pin 2 is GND and Pin 4 is +5V
Easy enough?
Hi,
Any updates on the testing of the 900x?
I am really interested in knowing if the latency of PPM is good enough as well as reliability.
I already have a couple of 900+ but they are incompatible with the 900x so im not sure if it is worth it.
Thanks for your comments.
MM
Hey, I know this is an old thread.
Did you manage to get this working?
I’ve set it up the same as you, but to no avail.
I did get it working. Using it to drive a gimbal, I setup failsafe values to keep the servo from doing unwanted moves during failsafe.
Do you think you could send a screenshot of your radio parameters from modem tools?
the biggest mistake i see people make
is you must set one as ground unit and the other air and one
and the ground unit as ppm in and the air unit as ppm out
and on the same firmware
it must be better than RFDSiK V3.09 rfd900x.bin
been using V3.16 for awhile now