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Communication failing between CR1000X and A3LA-R Iridium modem

Technician Aug 3, 2022 05:36 PM

Currently I'm running a test setup involving a pc acting as a server and a datalogger acting as a client, my goal is to make the server an client communicate with eachother wirelessly using The Iridium Network. The setup is as follows:


A Windows pc is running Loggernet 4.7 and wants to connect to the client/datalogger through Loggernet by choosing the dataloger form the "Stations" tab and clicking the "Connect" button.

From the Windows pc a RS-232 cable is connected directly to a "HRC-24-8R" datakit. The Datakit is connected to the A3LA-R modem and the modem is connected to a passive antenna. The datakit is also connected to a Iridium handset and a power source, supplying both the modem and the handset with power.


The CR1000X datalogger is connected to a "SC105 CS I/O to RS-232 interface" by a RS-232 cable, from the CSI/O-port on the datalogger. The SC105 is then connected to the datakit which is hooked up to the same type of modem, handset and antenna as the server. The datalogger is supplied with 12V of power. 

The server and client are not in any way connected by any wires as they will have to communicate wirelessly through the Iridium network.

Both modems have an Iridium simcard installed and i am using their respective datanumbers. 

My problem is that when I click the "Connect" button in loggernet on the server, the handset on the server side says "Data call in progress" and the handset on the client side is saying "Incomming data call". This to me indicates that the Iridium network setup within Loggernet is correct.

Sadly I'm not able to communicate with the datalogger on the client side and the connection eventullay times out on the server side.

I've tried to connect a PC to the datalogger and using the "terminal emulator" within loggernet to communicate with the modem using "AT-commands" this works fine and I get the correct response back from the modem.

To me all this indicates that the problem must be on the client side, and more pricesly be a "mismatch" or an error between the CR1000X and the SC105 interface, since the datacall is not able to pass all the way through to the datalogger. 

In the code on the datalogger the modem is setup using the following AT-commands:

Public initstring As String = "AT+IPR=5,1S0=1&K0&W0&Y0"+CHR(13)

I've checked that the SC105 is set up using baud rate 9600 like the modem.

In loggernet on the serverside, I have used the "edit modem database" button to make a userdefined modem with the following settings:

Reset string: &F

Initialization string: +cbst=0,0,1

Any help would be appricated.

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