ABB FSO-21 - Profisafe Description; Profisafe Message Format

200 PROFIsafe
PROFIsafe description
 PROFIsafe message format
The FSO module supports only the PROFIsafe short frame format. The short frame
supports a maximum of 12 octets of user data. The frame also includes a CRC (3
octets) and one Status/Control Byte octet. Therefore, the maximum frame size of the
message is 16 octets.
Control Byte and CRC2 bit order
PROFIsafe messages sent from the safety PLC to the FSO module include the
F-Output user data, the Control Byte and CRC2.
This table shows the bit order of the Control Byte and CRC2.
N
o
is the length of F-Output user data.
Data F-Input / F-Output user data Status / Control Byte CRC2
Size (octets) Max. 12 1 3
Octet Bit Name Description
Control Byte
N
o
7 Reserved The value is ignored.
6 Reserved The value is ignored.
5 Toggle_h Toggle bit
4 Activate_FV Fail-safe values (FV) to be activated
3 Use_TO2 Use F_WD_Time_2 (secondary watchdog).
Not in use. The value is ignored.
2 R_cons_nr Reset Vconsnr_d
1 OA_Req Operator acknowledgement requested
0 iPar_EN Parameter assignment deblocked.
Not in use. The value is ignored.
CRC2
N
o
+1 7 CRC bit 23 Octet 3 (MSB) of 24 bit CRC
…
0 CRC bit 16
N
o
+2 7 CRC bit 15 Octet 2 of 24 bit CRC
…
0 CRC bit 8
N
o
+3 7 CRC bit 7 Octet 1 (LSB) of 24 bit CRC
…
0 CRC Bit 0