I am sorry to hear that you are experiencing problems with your TC-08. The serial cable that you need to use is straght through. ie 1 - 1, 2 - 2,..., 9 - 9.
If you have made your own I would advise checking the conformity to ensure that the pin set up is correct. Once you have done this and confirmed cable is correct, I would advise that you check the voltage available form you serial port. The TC-08 requires a + and - voltage of about 7 volts, if it is not supplied with these voltage then the unit will not work and connection not possible.
Pin 5 - gnd
Pin 4 - -7 volts
Pin 7 - +7 volts
Start Picolog up and then try to connect to the TC-08 through the New Settings configuration routine. Then disconect the serial cable from the TC-08 and test the above pins with a multimeter.
If your PC is not supplying the correct voltage level you have to possible options, power the TC-08 externally, for which I can provide a diagram, or use a USB to Serial Port Adapter.
If you would like to recieve the diagram please send a request to:
requesting the external power supply diagram for serial products.