TMO Questions

[AlphaAssault]

Ive got the TMO software for my laptop, but am confused about the hardware aspect of TMO. two questions:

1) do you have to have a TMO chip to use the TMO software? or is the TMO chip i keep reading about something different?

2) what kind of cable do I need and where do i get it? ive read that you need a special serial-to-USB adapter to use the cable with a laptop, but was curious if there is a special cable that will work without the adapter. any input on this would be appreciated.

 

[steve]

Ive got the TMO software for my laptop, but am confused about the hardware aspect of TMO. two questions:

1) do you have to have a TMO chip to use the TMO software? or is the TMO chip i keep reading about something different?

2) what kind of cable do I need and where do i get it? ive read that you need a special serial-to-USB adapter to use the cable with a laptop, but was curious if there is a special cable that will work without the adapter. any input on this would be appreciated.

1. No, the chip and logging software are independent.

2. You need a logging cable. The original was a powered active level converter but a simple passive cable like shown in the tech archives here will work. You also neeed a serial port or a USB to serial converter that supports the non-standard 1G serial data rate like the Keyspan HS19-US or some other FTDI based converted.

 

[AlphaAssault]

The original was a powered active level converter but a simple passive cable like shown in the tech archives here will work.

which tech archive? i went through all those and didnt see anything about a logging cable for laptops.

 

[AlphaAssault]

Ok, I just bought a Keyspan USA-19HS and a regular DSM logging cable (serial port connection). does this sound correct, or is there something else i need?

 

[steve]

If you got the PC version of the logging cable then it should work.

 

[AlphaAssault]

im pretty sure its the PC version. whats the difference?

 

[steve]

im pretty sure its the PC version. whats the difference?

There are two types of RS-232 communication devices, Data Terminal Equipment and Data Communications Equipment. This dates back from teletypes and modems and defines what signals are on what pins and which direction they go.

The IBM PC serial port is configured as a DTE and designed for connecting a modem to it. It transmits it's data on pin 2 and receives data on pin 3. The device that plugs into the port is configured as a DCE and receives data on pin 2 and transmits it on pin 3.

The Palm serial hotsync cable is designed to plug into a PC serial port and therefore is configured as a DCE.

A datalogger cable intended for use with a PC is configured as a DCE and has a female DB9 connector.
A datalogger cable intended for use with a Palm PDA is configured as a DTE and has a male DB9 connector.

DCE's can't talk to DCE's nor can DTE's talk to DTE's because they both try to transmit on the same pin and receive on the other. That's where a null modem adaptor comes in. At minimum it switches pin 2 on one side to pin 3 on the other and pin 3 on the first side to pin 2 on the other. That takes care of the electrical side of things. On the mechanical side you need something to account for the connector sex because both connectors are likely to be the same.

All that said, if the logger cable you received plugged right into the device your using then it should be properly set up for the DTE/DCE issue, not that I haven't seen screwed up cables.