B&B Electronics RS-232 to J1939 Converter CE 1939STB - Manual (Page 25)

1939STB4600 Manual 23
B&B Electronics Mfg Co Inc – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph 815-433-5100 - Fax 815-433-5104
B&B Electronics Ltd – Westlink Commercial Park – Oranmore, Galway, Ireland – Ph +353 91 792444 – Fax +353 91 792445
Byte 8
(Shown in Table 30)
Bits 7, 6, 5, 4, and 3 of Byte 8 along with Bits 2, 1, and 0 of Byte 7 make up
the first part of the PDU (Protocol Data Unit). The first 8 bits are the PDU
format. The values for specific formats will have to be supplied by the user.
Bits 2, 1, and 0 of Byte 8 and bits 7, 6, 5, 4, and 3 of Byte 9 make up the
second part of the PDU. The eight bits are the PDU specific. Values for the
PDU specific will have to be supplied by the user .
NOTE: It is a common practice to combine the first and second parts of the
PDU into a single number. When given the PDU as a single number, bit 2 of
byte 7 is the MSB and bit 3 of byte 9 is the LSB.