beautypg.com

Simple instruction set control, Host-to-switcher communications, Switcher-initiated messages – Extron Electronics DTP T USW 233 User Guide User Manual

Page 18: Error responses, Timeout

background image

DTP T USW 233 • Remote Control

13

Simple Instruction Set Control

The DTP T USW 233 switching transmitter can be remotely controlled using SIS commands
from a host device such as a computer or control system via its rear panel Remote RS-232
port (see

item

h

on page 5) or front panel Configuration (USB) port (see

item

a

on

page 8).
The default serial port protocol of the port is as follows:

9600 baud

No parity

8-bit

No flow control

1 stop bit

Host-to-Switcher Communications

SIS commands consist of one or more characters per field. No special characters are
required to begin or end a command character sequence. When a command is valid, the
switcher executes the command and sends a response to the host device. All responses
from the switcher to the host end with a carriage return and a line feed (CR/LF =

]

), which

signals the end of the response character string. A string is one or more characters.

Switcher-Initiated Messages

When a local event occurs, such as a front panel operation, loss or restoration of an input
signal, or an error condition, the switcher responds by sending a message to the host. The
switcher-initiated messages are listed below:
©

Copyright

20yy

,

Extron

Electronics

DTP

T

USW

233

,

Vx

.

xx

,

60

-

nnnn

-

nn

]

The switcher issues the copyright message when it first powers on.

Vx

.

xx

is the firmware

version number and

60

-

nnnn

-

nn

is the part number.

In

n

All

]

The switcher also sends the In

n

message whenever the selected input is changed.

n

is the

input number. A

0

in the

n

field indicates no input is selected.

Error responses

When the switcher receives a valid SIS command, it executes the command and sends a
response to the host device. If the switcher is unable to execute the command because the
command is invalid or it contains invalid parameters, the switcher returns an error response
to the host. The error response codes are:
E01 — Invalid input channel number (out of range)
E06 — Invalid channel change
E10 — Invalid command
E13 — Invalid parameter

Timeout

Pauses of 10 seconds or longer between command ASCII characters result in a timeout.
The command operation is aborted with no other indication.