Eurotherm 6100, User Manual

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100/180MM DISTRIBUTED GRAPHIC RECORDER: USER GUIDE
HA029324
Issue 11 Oct 14 User Guide
Page 272
19 20 21 22 23 25 26 27 28 29 30 31 33 34 35 36 37 38 39 41 42 44 45 46 47 49 50 51 52 53 54 55 1 2 3 4 5 6 7 8 10 11 12 13 14 15 16 17 9 18 24 32 40 43 48 56 57 58 59 60
42 61 74 63 68 73 74 6F 70 70 65 64 62 65 63 61 75 73 65 6F 66 62 65 6C 74 66 61 69 6C 75 72 65 30 34 2F 30 34 2F 30 32 31 36 3A 33 31 3A 30 35 20 20 20 20 20 20 20 20 42 54 30 31
19 20 21 22 23 25 26 27 28 29 30 31 33 34 35 36 37 38 39 41 42 44 45 46 47 49 50 51 52 53 54 55 1 2 3 4 5 6 7 8 10 11 12 13 14 15 16 17 9 18 24 32 40 43 48 56 57 58 59 60
20 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Message
Extension
message
(Space + 59 null
characters)
Space = hex 20; Null = 00
19 20 21 22 23 25 26 27 28 29 30 31 33 34 35 36 37 38 39 41 42 44 45 46 47 49 50 51 52 53 54 55 1 2 3 4 5 6 7 8 10 11 12 13 14 15 16 17 9 18 24 32 40 43 48 56 57 58 59 60
42 61 74 63 68 73 74 6F 70 70 65 64 62 65 63 61 75 73 65 6F 66 62 65 6C 74 66 61 69 6C 75 72 65 30 34 2F 30 34 2F 30 32 31 36 3A 33 31 3A 30 35 20 20 20 20 20 20 20 00 00 00 00 00
Character no.
English message
ASCII (Hex)
8.2.5 Text messages
In order to increase ef fi ciency, it is possible to set the system to transmit screen messages (e.g. alarm on/off)
only when a new message occurs. This is done by continuously polling the ‘Text Length’ parameter (in group
data - section 8.4.4 ) to see if its value is non-zero. (This parameter contains the character count of the latest
message to occur since the last poll.)
If ‘text length’ is non-zero, the host must access the parameter ‘Read Text’ (also in group data) to read the
message, and it must also reset the ‘Text Length’ parameter to zero. This causes the recorder to look for any
further messages in the queue, and if there are, it will load the latest message into the area accessed by ‘Read
Data’, and then set ‘Text Length’ to the length of the new message. If the host fails to set Text Length to zero
after reading a message, no new messages will be read.
If ‘Text Length’ is zero, no new messages have been generated since the last poll.
LONG MESSAGES
All messages are terminated with a null character.
Messages of up to 60 characters (including the time and date and the terminating ‘null’) can be read by the
master device in a single transaction.
If the message contains more than 60 characters, one or more continuation messages of up to 60 characters
each are placed in ‘Read Text’, as soon as the previous message has been con fi rmed as ‘read’. The master can
continue to read all these messages, until it detects a ‘null’ character. Intelligent masters can then re-assemble
the characters into a single message. Non-intelligent masters can treat the continuation messages as separate
messages sent at the same time as the fi rst message.
Notes:
1. If any of the messages is of less than 60 characters, the unused part of message is
fi lled with ‘null’
characters (example 1). Thus, by reading character 60, the master can determine either that this is
the last message (character 60 = ‘null’), or that there is at least one message to follow (character 60
is not ‘null’).
2. Continuation messages cannot contain only null characters. For this reason, if the message itself
(i.e. excluding fi nal ‘null’ characters) is exactly 60 characters long (or a multiple of 60 characters
long) then the fi nal extension message contains a space, followed by 59 ‘nulls’ (Example 2).
3. Time and date appear only in the main message, not the continuation message(s).
Example 1
Message of less than 60 characters
Example 2
Message of exactly 60 characters