B&B Electronics 1939STB manual Byte

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.

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