Programming - Balluff BIS C-6 0 RS 232 Serie Handbuch

C-6_0-007-00_836905_E_0704.p65
35
Explanation of
selected telegram
contents
36
BCC Block Check
Variants for finish
with BCC,
Terminator
36 english
Programming Information
Start address and The start address (A3, A2, A1, A0) and the number of bytes to send
no. of bytes (L3, L2, L1, L0) are transmitted as ASCII characters. For the start address
a range of 0000 to 8191 and for the number of bytes 0001 to 8192 can be
used. A3 ... L0 stand for 1 ASCII character each.
Please note: Start address + number of bytes may not exced the
Head number For the 'L' (read with head select and page size) and
and block size 'P' (write with head select and page size) commands, first the number of
the read/write head K ('1' or '2') and then the block size B ('0', '1') of the
data carrier are sent.
B = '0' corresponds to 64 bytes,
B = '1' corresponds to 32 bytes.
Acknowledgement The <ACK> '0' is sent by the identification system if the serially
transmitted characters were correctly recognized and a data carrier is
within
the active zone of a read/write head. FOr the 'R' command, <ACK> '0' is
only given if the data are ready for sending.
<NAK> + 'Error No.' is sent as an acknowledgement if an error is detected
or if there is no data carrier within the active zone of a read/write head.
Start <STX> starts data transmission.
Bytes The data are transmitted code-transparent (not converted).
sent

Programming

The BCC block check is formed as an EXOR of the serially transmitted binary characters of
the telegram block. Example: Read 128 bytes starting at address 13.
The command line without BCC is: 'L 0013 0128 20'. The BCC is formed:
'L
0
0
1
3
0
1
2
8
2
0'
Block check result: BCC
If necessary the finish using block check BCC can be replaced with a special ASCII character.
This is:
– Carriage Return 'CR'
For hosts which always require a terminator character, this must always be included in the
telegrams. Available are:
– Carriage Return 'CR' or
– Line Feed with Carriage Return 'LF CR'.
The various protocol variations are represented on the following page (see also page 13/14).
data carrier capacity.
= 0100 1100 EXOR
= 0011 0000 EXOR
= 0011 0000 EXOR
= 0011 0001 EXOR
= 0011 0011 EXOR
= 0011 0000 EXOR
= 0011 0001 EXOR
= 0011 0010 EXOR
= 0011 1000 EXOR
= 0011 0010 EXOR
= 0011 0000 EXOR
= 0100 0111 = 'G'
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english