&²
&²
All transmitted command characters must be upper case ASCII. All characters are
echoed by the receiver, except for the Unit Number (i.e., byte #3) which is decre-
mented if greater than zero (0). This permits daisy-chaining two or more receivers
from one serial port.
(UURUUHVSRQVHV
Table 14 shows command error and overrun error response frame information.
?
The command error message displays if the receiver cannot recognize the com-
mand, or if an internal microprocessor operating error or error condition exists.
1
Decoder is addressed when first unit (1) received
2
Carriage Return
3
Line Feed
&
The overrun error message displays if the receiver cannot process the command
completely, and/or if the command becomes corrupted during transmission.
%LW(UURU5DWH%(5
The BER command is available for polling the receiver to display the current Bit
Error Rate of the decoded digital signal (errors per second). Observe the following
syntax.
SA1BER
BER
polls the receiver for the current Bit Error Rate (digital signal), where #.#E-# is
the number is bit errors in a 1 million bit sample, expressed in scientific notation.
The receiver responds by displaying the following.
BER=#.#E-#
&KDQQHO
The Channel command is available for polling the receiver to display the current
channel, or for changing the channel. Observe the following syntax.
SA1CH=###
CH
polls the receiver for the current channel.
CH=###
changes the current channel.
The receiver responds by displaying the following.
CH=###
### can be any virtual channel number from 0 through 500.
Table13. Command/Response frames
Command frame
Byte
Length
Data
Description
1
1
S
Start character #1
2
1
A
Start character #2
3
1
1-9
:
Unit Number (in chain)
1
Precedes next ASCII character (if more than 9 units in
chain)
4
n
Command code and parameters
4 + n
1
<CR>
2
End of message
Response frame
1
1
<LF>
3
Line Feed
2
n
Command Response
2 + n
1
<CR>
Carriage Return
3 + n
1
<LF>
Line Feed
4 + n
1
>
Ready for next message
Table14. Command/Overrun errors
Command error frame
Byte
Length
Data
Description
2
1
?
Command error response
Overrun error frame
2
1
&
Overrun error response
