Rockwell Automation 1203-SSS Smart Self-powered Serial Converter - Manual (Page 45)

Glossary
A Application Code
Code that runs in the adapter after the boot code calls it. It performs the
normal operations of the system.
B
BCC
Block Check Character. An error detection scheme where the 2’s
complement of the 8-bit sum (modulo-256 arithmetic sum) of all data
bytes in a transmission block. It provides a means of checking the
accuracy of each message transmission.
Boot Code
Code that runs when the adapter first receives power. It checks basic
operations and then calls the application code.
Bus Off
A bus off condition occurs when an abnormal rate of errors is detected
on the Control Area Network (CAN) bus in a device. The bus-off device
cannot receive or transmit messages. This condition is often caused by
corruption of the network data signals due to noise or data rate
mismatch.
C
CRC
Cyclic redundancy check. An error detection scheme where all of the
characters in a message are treated as a string of bits representing a
binary number. This number is divided by a predetermined binary
number (a polynomial) and the remainder is appended to the message as
a CRC character. A similar operation occurs at the receiving end to prove
transmission integrity.
D DF1 Protocol
A peer-to-peer link layer protocol that combines features of ANSI
X3.28-1976 specification subcategories D1 (data transparency) and F1
(two-way simultaneous transmission with embedded responses).
DF1 Rate
A unit of signaling speed equal to the number of discrete conditions or
signal events per second. It is also called “baud rate” or “serial port rate.”