bit. Generally, when the ARINC 429 word format is illustrated with Bit 32 to the left, the numeric representations in the data field are read with the most significant bit on the left. However, in this particular bit order presentation, the Label field reads with its most significant bit on the right. Like CAN Protocol Identifier Fields, ARINC 429 label fields are transmitted most significant bit first. However, like UART Protocol, Binary-coded decimal numbers and binary numbers in the ARINC 429 data fields are generally transmitted least significant bit first. Some equipment suppliers publish the bit transmission order as First bit > 8, 7, 6, 5, 4, 3, 2, 1, 9, 10, 11, 12, 13 … 32 < Last bit. The suppliers that use this representation have in effect renumbered the bits in the Label field, converting the standard's MSB 1 bit numbering for that field to LSB 1 bit numbering. This renumbering highlights the relative reversal of "bit endianness" between the Label representation and numeric data representations as defined within the ARINC 429 standard. Of note is how the 87654321 bit numbering is similar to the 76543210 bit numbering common in digital equipment; but reversed from the 12345678 bit numbering defined for the ARINC 429 Label field. This notional reversal also reflects historical implementation details. ARINC 429 transceivers have been implemented with 32-bit shift registers. Parallel access to that shift register is often octet-oriented. As such, the bit order of the octet access is the bit order of the accessing device, which is usually LSB 0; and serial transmission is arranged such that the least significant bit of each octet is transmitted first. So, in common practice, the accessing device wrote or read a "reversed label" (for example, to transmit a Label 2138 [or 8B16] the bit-reversed value D116 is written to the Label octet). Newer or "enhanced" transceivers may be configured to reverse the Label field bit order "in hardware." Word format Each ARINC 429 word is a 32-bit sequence that contains five fields: Bit 32 is the parity bit, and is used to verify that the word was not damaged or garbled during transmission. Every ARINC 429 channel typically uses "odd" parity - there must be an odd number of "1" bits in the word. This bit is set to 0 or 1 to ensure that the correct number of bits are set to 1 in the