Teledyne GFC-7000T - Trace CO2 Analyzer - manual - Manual (Page 268)

Troubleshooting Model GFC7000TA Carbon Dioxide Analyzer
Teledyne Analytical Instruments 250
10.5.10.2. Troubleshooting Analyzer/Modem or Terminal Operation
These are the general steps for troubleshooting problems with a modem connected to a Teledyne
Instruments analyzer.
1. Check cables for proper connection to the modem, terminal or computer.
2. Check to make sure the DTE-DCE is in the correct position as described in Section 6.10.5.
3. Check to make sure the set up command is correct (See Section 6.13.2.7)
4. Verify that the Ready to Send (RTS) signal is at logic high. The GFC 7000TA sets pin 7 (RTS) to
greater than 3 volts to enable modem transmission.
5. Make sure the BAUD rate, word length, and stop bit settings between modem and analyzer
match, See Section 6.10.7.
6. Use the RS-232 test function to send “w” characters to the modem, terminal or computer; See
Section 6.10.8.
7. Get your terminal, modem or computer to transmit data to the analyzer (holding down the space
bar is one way); the green LED should flicker as the instrument is receiving data.
8. Make sure that the communications software or terminal emulation software is functioning
properly.
Further help with serial communications is available in a separate manual “RS-232 Programming Notes”
Teledyne Instruments part number 013500000.