Last modified by Bjørnar Ruud on 2021/03/18 10:47
From version 24.1
edited by Kristian Lingsom
on 2017/10/16 13:39
To version 24.2
edited by Kristian Lingsom
on 2017/10/16 13:45
Change comment: There is no comment for this version

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79 79  All fixed length “n” data elements are assumed to be right justified with leading zeroes. All other fixed length data elements are left justified with trailing spaces. In all “b” data elements, blocks of 8 bits are assumed to be left justified with trailing zeroes.
80 80  
81 81  
82 +== Message protocol ==
82 82  
84 +All messages are transferred using TCP/IP sockets.
85 +
86 +The message will be encapsulated in a transmission frame as follows:
87 +
88 +* The first 4 digits contain the length of the message in ASCII (decimal value, most significant digit first). The length field includes all bytes from the first byte of the message ID up to the last byte of the last field.
89 +* This 4-digit length field is immediately followed by the message ID, also in ASCII (decimal value, most significant digit first).
90 +* An 8 byte message bitmap, which is a binary field (so not ASCII encoded).
91 +* Message fields, which could be ASCII or binary encoded. The fields with format ‘n, ns, an, ans, anp or x’ are ASCII encoded, while the fields with format ‘b’ are binary encoded. The following conventions shall be applied to all data elements:
92 +** All fixed length numeric data element values shall be right justified with leading zeroes.
93 +** All fixed length data elements with alphabetic or special characters shall be left justified with trailing blanks.
94 +** All fixed length binary data elements shall be right justified with leading zeroes.
95 +** The position of a character or a bit in a data element shall be counted from the left beginning with one (1).(See also section 5.1 Attribute specification in [01])
96 +** No trailer is included.
97 +
98 +Example: An imaginary message which consists only of a message ID “0300” and an empty bitmap (all zeros) will be transmitted as follows:
83 83  
100 +
101 +|=Length|=Message ID|=Bitmap
102 +|=0x30 0x30 0x31 0x32|=0x30 0x33 0x30 0x30|=0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
103 +
104 +