Rockwell Automation 1760-xxxx Pico GFX-70 Controllers User Manual - Manual (Page 321)

Publication 1760-UM002B-EN-P - March 2005
Pico-Link and Point-to-Point Serial Connections 6-15
Network Transmission Security
The Pico-Link is a CAN-based network. CAN is used in cars and commercial
vehicles in all areas. The same fault recognition capability with data transfer
applies as with CAN. A BOSCH study relating to undiscovered and corrupt
messages determined the following:
The probability of non-discovery of a corrupted message (residual error
probability) is: < 10
-10
message error rate.
The message error rate depends on:
• Bus loading
• Telegram length
• Malfunction frequency
• Number of stations
Example:
Network with:
• 500 kBaud
• average bus load 25%
• average operating time 2000 h/year
• average error rate of 10
-3
,
i.e.: 1 message is faulty every 1000
• transmission of 1.12 x 10 10
messages per year of which 1.12 x 10
7
messages are faulty
• residual error probability: r < 10 -10
x 10
-3
= 10
-13
This means: one of 10
13
messages is so corrupt that the fault cannot be
recognized as such. For a network, this corresponds to a working time of
approximately 1000 years.