Elecraft KX3 Programmers Reference - Manual (Page 3)

3
Command Format
Note: In the remainder of this document, K3 references apply to the KX3 as well unless otherwise noted.
Commands sent from the computer to the K3 are considered either GETs or SETs. GET commands are used by the
computer to get information from the K3; the K3 will then provide an appropriate response message (RSP). SET
commands are sent by the computer to change the radio's configuration or initiate an event. A SET can be followed
by a GET to verify the new settings, or the auto-info mechanism can be used for confirmation that something has
changed (see AI in the Meta-commands section).
SET commands use 2 or 3 characters, optional data fields, and a terminating semicolon (;). Examples:
KS020; Computer sets CW speed to 20 WPM (data = 020)
MD1; Computer selects LSB mode (data = 1)
Many SET commands have a corresponding GET command, which is just the command letters with no data. The
data format of the response message from the K3 (RSP) is usually identical to the format of the SET data.
Exceptions are noted in the command descriptions.
Characters sent to the K3 can use either upper or lower case. The K3 will always respond with upper case, except
when a lower-case character is a place-holder for a special symbol (e.g., the VFO B display command, DB).
Sub Receiver/VFO B Commands ($), Linked VFOs, and Diversity Mode
Some commands target VFO B (and the sub RX, in the case of the K3) if ($) is added after the command prefix.
Examples include AG$, RG$, MD$, BW$, FW$, LK$. This is indicated in the reference section by a $ in the
command title. (Some commands target VFO B itself and do not need the ‘$’, including FB, UPB, DNB, and DB.)
If the VFOs are linked (see LN), commands that affect the VFO A frequency also change VFO B. This includes
FA, UP, DN, RU, RD, and RC. In Diversity mode, BW, FW and MD match the VFO B/sub receiver filter and
mode settings, respectively, to the main receiver.
Extended Commands
Some commands have an extended data format which provides enhanced functionality or backward compatibility
with older software applications. Such commands should be avoided in switch macros because of the need to use a
meta-command to enable extended functionality (see Meta-commands section). Alternatives are available. For
example, the BW (bandwidth) command should be used in macros rather of the legacy FW command, which
depends on meta-command settings.
Response Time
The K3 will typically respond in less than 10 milliseconds. General worst-case latency is around 100 ms, except for
commands that change bands, which can take up to 500 ms.
Since the K3 provides a full-duplex interface, the computer can send the K3 commands at any time. Continuous,
fast polling (< 100 ms per poll for bar graph data in transmit mode, for example) should be carefully tested to
ensure that it isn’t affecting radio operation. Polling during transmit not be used unless necessary.
Busy/Limited Access Indication (?;)
Some commands cannot be safely handled when the K3 is in a busy state, such as transmit, or in a limited-access
state, such as BSET or VFO A/B reverse (REV switch). If a command cannot respond due to such a condition, the
K3 will return “?;”. Future firmware releases will gradually become less restrictive in this regard.
You can use the TQ command to see if the K3 is in transmit mode, and the icon/status command (IC) to check for
BSET mode (byte a, bit 6).