// Status=review

_WSJT-X_ offers CAT (Computer Aided Transceiver) control of the
relevant features of most modern transceivers.  To configure the
program for your radio, select the *Radio* tab.

image::images/RadioTab.png[align="center",alt="Radio Tab"]

- Select your radio type from the drop-down list labeled *Rig*, or
*None* if you do not wish to use CAT control.

- Alternatively, if you have configured your station for control by
*DX Lab Suite Commander*, *Ham Radio Deluxe*, *Hamlib NET rigctl*, or
*OmniRig*, you may select one of those program names from the *Rig*
list.  In these cases the entry field immediately under _CAT Control_
will be relabeled as *Network Server*.  Leave this field blank to
access the default instance of your control program, running on the
same computer. If the control program runs on a different computer
and/or port, specify it here.  Hover the mouse pointer over the entry
field to see the required formatting details.

- Select *OmniRig Rig 1* or *OmniRig Rig 2* to connect to an _OmniRig_
server running on the same computer.  Note that _OmniRig_ is available
only under Windows.

- Set *Poll Interval* to the desired interval for _WSJT-X_ to query
your radio.  For most radios a small number (say, 1 – 3 s) is
suitable.

- _CAT Control_: To have _WSJT-X_ control the radio directly rather
than though another program, make the following settings:

* Select the *Serial Port* used to communicate with your radio. 

* _Serial Port Parameters_: Set values for *Baud Rate*, *Data Bits*,
*Stop Bits*, and *Handshake* method.  Consult your radio's user guide
for the proper parameter values.

* _Force Control Lines_: A few station setups require the CAT serial
port’s *RTS* and/or *DTR* control lines to be forced high or
low. Check these boxes only if you are sure they are needed (for
example, to power the radio serial interface).

- _PTT Method_: select *VOX*, *CAT*, *DTR*, or *RTS* as the desired
method for T/R switching.  If your choice is *DTR* or *RTS*, select
the desired serial port (which may be the same one as used for
CAT control).

- _Transmit Audio Source_: some radios permit you to choose the
connector that will accept Tx audio.  If this choice is enabled,
select *Rear/Data* or *Front/Mic*.

- _Mode_: _WSJT-X_ uses upper sideband mode for both transmitting and
receiving.  Select *USB*, or choose *Data/Pkt* if your radio offers
such an option and uses it to enable the rear-panel audio line input.
Some radios also offer wider and/or flatter passbands when set to
*Data/Pkt* mode.  Select *None* if you do not want _WSJT-X_ to change
the radio's Mode setting.

- _Split Operation_: Significant advantages result from using *Split*
mode (separate VFOs for Rx and Tx) if your radio supports it.  If it
does not, _WSJT-X_ can simulate such behavior.  Either method will
result in a cleaner transmitted signal, by keeping the Tx audio always
in the range 1500 to 2000 Hz so that audio harmonics cannot pass
through the Tx sideband filter.  Select *Rig* to use the radio's Split
mode, or *Fake It* to have _WSJT-X_ adjust the VFO frequency as
needed, when T/R switching occurs.  Choose *None* if you do not
wish to use split operation.

When all required settings have been made, click *Test CAT* to test
communication between _WSJT-X_ and your radio.  The button should turn
green to indicate that proper communication has been established.
Failure of the CAT-control test turns the button red and displays an
error message.  After a successful CAT test, toggle the *Test PTT*
button to confirm that your selected method of T/R control is working
properly.
