Dte and dce communication, Comm port communication modes – Teledyne GFC-7000E - Trace CO2 Analyzer User Manual

Page 96

Model GFC7000E Instruction Manual

Operating Instructions

04584 Rev A1

Table 6-15: COM1 and COM2 DB-9 Pin Assignments

Pin #

COM1 (RS-232)

COM2 (RS-232)

COM2 (RS-485)

Not used

Transmit Data*

Receive Data

DATA -

Receive Data*

Transmit Data

Data +

Not used

Signal Ground

Not used

DATA SET READY*

DATA SET READY

Not used

REQUEST TO SEND*

(=DTE Ready)

REQUEST TO SEND

Not used

* Configurable for COM1 at rear panel using the DTE-DCE switch

6.10.5. DTE and DCE Communication

RS-232 was developed for allowing communications between data terminal equipment (DTE) and

data communication equipment (DCE). Basic terminals always fall into the DTE category whereas
modems are always considered DCE devices. The difference between the two is the pin
assignment of the Data Receive and Data Transmit functions. DTE devices receive data on pin 2

and transmit data on pin 3, DCE devices receive data on pin 3 and transmit data on pin 2.

To allow the analyzer to be used with terminals (DTE), modems (DCE) and computers (which can

be either), a switch mounted below the serial ports on the rear panel allows the user to switch
between the two functions.

6.10.6. COMM Port Communication Modes

Each of the analyzer’s serial ports can be configured to operate in a number of different modes,

listed in Table 6-16, which can be combined by adding the mode ID numbers. For example, quiet
mode, computer mode and internet-enabled mode would carry a combined mode ID of 11, the

standard configuration on the MGFC7000E COM2 port. Note that each COM port needs to be
configured independently.