Rose Electronics Porter User Manual

Page 29

PORTER INSTALLATION AND OPERATIONS MANUAL

Ready (Check DSR) command
This command allows a program to determine if a given serial port’s DSR (pin 6) is in the

ready state (+12V), or the busy state (-12V). The syntax of this command is prefix + port

number 0-8. A single byte is returned: ASCII “0” if the specified port is in the busy state,

and “1” if it is in the ready state. Note that a port with no device connected will read as

“ready” due to the internal pull-up resistor provided for pin 6.
Since this command returns an answer, you must ensure that no reverse channel data

(data coming from ports 1-8) is present when this command is issued. The safest way to

use this command is to use the connect 9 (Null Destination) command first, then after

issuing the Ready command and receiving its answer re-issue the appropriate connect

command to re-connect.
If this command is issued when there is reverse channel data traffic, it may not respond.
Setup (Configuration) menu commands
The configuration menu is invoked by the prefix + S command. You would normally not

issue this command except by manual entry from a communication program or dumb

terminal. For more information on the configuration menu see “The Configuration Menu”.
Timeout (command purge) command
This allows changing the command purge timeout. The timeout value may range from

000-255. Setting a value of 000 disables the command purge timeout. The syntax of this

command is prefix + T + nnn. Leading zeros are required. For more information on te

command purge timeout se the “Configuration Menu” section under “Change command

purge timeout value”.
Wait command
The Wait command causes two things to happen to the port n that it is used on. First,

any transmission that may be in progress is suspended. Second, the port’s DTR is set to

low, and if the port is configured for X-on/X-off operation a X-off character is sent. This

state is cleared with the Go command. The syntax of this command is prefix + W + port

number.
Zero (clear) command
This command is used to clear the buffer and cancel any pending data transfers on the

port specified. This command should be used prior to using the copy command to

ensure that the proper data will be copied. Zero is set for an individual port buffer by

sending the prefix + Z + port number.