ADC-16 and wireless radio modems

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ADC-16 and wireless radio modems

Post by Guest » Sat Oct 02, 2004 7:38 pm


I have just acquired an ADC16 and a pair of RF solutions RS232C-868FR Radio Modems to transmit data. I am having problems getting them to work together.

I am trying to power the whole lot off 9V batteries; hence I have one for each radio modem and then a pair to give me +9v;-9v and 0v as it appears that the modem will not power the logger. I have created a customised serial cable with GND going to pin 5; +9v going to pin 7 and -9V going to pin 4 and when I stick a voltmeter on the +-5v on the terminal board I get the expected readings. I have then connected all of the other pins strainght through to the radio modem.

However when I try to get picolog record to talk to the logger I get a unit not found error message. I am fairly sure the radio modems are chatting away as there are suitable RX and TX lights when I use the suppied software to send data; so I think I have got something wrong with my connecting cable. Any help would be appreciated.


(the radio modem pins are 2;tx 3;rx, 4DTR, 5;GND, 7;RTS, 8;CTS incase its important)


Post by Sarah » Wed Oct 06, 2004 9:21 am


thank you for your post, I am sorry to hear that you have been seeing this problem.

The pin configuration for the serial port of the ADC-16 is as follows:

Pin Name Usage
3 TX Data from the PC to the ADC-16
2 RX Data from the ADC-16 to the PC
7 RTS Held at a positive voltage (>7V) to power the ADC-16
5 GND 0V line
4 DTR Held at a negative voltage (<-7V) to power the ADC-16

One of the reasons you might not be seeing readings is that for some radio modems, there is a delay between sending text to the modem and its arrival at the other end, and a similar delay for the response from the unit. If, for example, the maximum possible delay is 150ms each way, 300ms total, the following text should be added to Win.INI so that the driver waits longer for each response:


Hope this helps.

Best Regards


ADC16 and Radio Modems

Post by Guest » Wed Oct 06, 2004 1:45 pm

Thanks for the post

I have spoken to both Pico Technical support and Rf Solutions at length about this issue. I have found that basically this setup is not going work. Unfortunately the ADC16 uses the RTS and CTS PINS for power. Inorder to power it, I need to break into the serial cable and supply a voltage to these PINS. However this means the modem will not send and recieve correctly as it needs these pins to be availible to it.

Therefore anyone wanting to use an ADC16 with a radio modem needs to check that the modem will work with a data logger working in this configuration.

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