Parker EME
Communication
192-120103 N13 C3I20T11 / C3I32T11 December 2010
297
RS232: O [$] Index , [$] Subindex = [$] Value [ ; Value2 ; Value3 ; ...]
RS485: Address O [$] Index , [$] Subindex = [$] Value [ ; Value2 ; Value3 ; ...]
The optional “$” preceding Index, Subindex and value stands for “Hex-input” which
means that Index, Subindex and the value to be transferred can also be entered in
hex (e.g.
O $0192.2=$C8
).
5.2.3.
Binary record
The binary record with block securing is based on 5 different telegrams:
2 request telegrams which the control sends to Compax3 and
3 response telegrams which Compax3 returns to the control.
Telegram layout
Basic structure:
Start code
Address
Number of data bytes - 1
Data
Block securing
SZ
A
L
D0
D1
...
Dn
Crc(Hi)
Crc(Lo)
The start code defines the frame type and is composed as follows:
Bit
7
6
5
4
3
2
1
0
Frame type
Frame identification
PLC
Gateway
Address
RdObj
read object
1
0
1
0
x
1
x
x
WrObj
write object
1
1
0
0
x
1
x
x
Rsp
response
0
0
0
0
0
1
0
1
Ack
positive command acknowledgement
0
0
0
0
0
1
1
0
Nak
Negative command acknowledgement
0
0
0
0
0
1
1
1
Bits 7, 6, 5 and 4 of the start code form the telegram identification; Bit 2 is always
“1”.
Bits 3, 1 and 0 have different meanings for the request and response telegrams.
The address is only necessary for RS484.
-> Compax3
the address bit (Bit 0 = 1 ) shows if the start code is followed by an address
(only for RS485; for RS232 Bit 0 = 0)
the gateway bit (Bit 1 = 1) shows if the message is to be passed on.
(Please set Bit 1 = 0, as this function is not yet available)
the PLC bit (Bit 3 = 1 ) allows access to objects in the PLC/Pop format
U16, U32: for integer formats (see bus formats: Ix, Ux, V2)
IEEE 32Bit Floating Point: for non integer formats (bus formats: E2_6, C4_3, Y2,
Y4; without scaling)
With Bit 3 = 0 the objects are transmitted in the DSP format.
DSP formats:
24 Bit = 3 Bytes: Integer INT24 or Fractional FRACT24
48 Bit = 6 Bytes: Real REAL48 (3 Byte Int, 3 Byte Fract) / Double Integer DINT48
/ Double Fractional DFRACT48
Compax3 ->
Bits 0 and 1 are used to identify the response
Bit 3 is always 0
The maximum number of data bytes in the request telegram is 256, in the response
telegram 253.
The block securing (CRC16) is made via the CCITT table algorithm for all
characters.
After receiving the start code, the timeout monitoring is activated in order to avoid
that Compax3 waits in vain for further codes (e.g. connection interrupted) The
timeout period between 2 codes received is fixed to 5ms (5 times the code time at
9600Baud)
Write object
Request telegrams
Response telegram
