Digidim 503AV / 505 RS232 AV Interface User Guide
Helvar Ltd.
Doc. No. 7860076
Page 13
Issue 8
8. Appendices
8.1. Return message format
Reply type
The ‘reply type’ is dependent upon the transmitted message type and source of
transmission. The return for a self-generated AV type 51 will be 64, as shown. However,
messages originating from other sources will differ. For example, those originating from a
DIGIDIM push-button panel will typically show a type return of 61. These variations are for
internal use by DIGIDIM components and are of no consequence to AV control. If return
messages are to be processed, it is recommended that the exact content of the reply type
byte is ignored.
Data formats
Some third party AV interface equipment display received data in different formats to
hexadecimal, and may even display received bytes in different formats, dependent upon
the data value. In such cases, the displayed data may appear to be a mixture of
hexadecimal and other formats, such as ASCII. This is entirely a function of the third party
equipment and the user should ascertain the details from the third party vendor.
As an example:
Transmit
03 51 01 10
Return
03 64 01 10
Displayed Return
03 d
01 10 (d = ASCII for hex 64)
In general, data bytes only within the range of 20h to 7Fh will be converted to the ASCII
character. The standard conversion will be as per the table below, but confirmation should
be gained from the third party vendor.
HEX
-0 -1 -2 -3 -4 -5 -6 -7 -8 -9 -A -B -C -D -E -F
2- SP
! ‘ # $ % & ’ ( ) * + , - . /
3- 0 1 2 3 4 5 6 7 8 9 : ; < = > ?
4- @ A B C D E F G H I J K L M N O
5- P Q R S T U V W X Y Z [ \ ] ^ _
6- ‘ a b c d e f g h i j k l m n o
7- p q r s t u v w x y z { | } ~ del
Note:
For more detailed listing of commands, refer to document ‘RS232 to DALI
Command List’ (7860077).
