B&B Electronics RS-232 to J1939 Converter CE 1939STB User Manual

Page 18

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16 1939STB4600

Manual

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 5

Table 24. Byte 5

Byte 5

Bit Function

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

MSGVAL

TXIE

RXIE

INTPND

Sets the message valid

1

0

Sets the message invalid

0

1

Transmit interrupt set

1

0

Transmit interrupt not set

0

1

Receive

interrupt

set 1

0

Receive not set

0

1

Interrupt has occurred

1

0

No

interrupt

pending

0

1

NOTE: The dark gray (white letters) should be set to this value when sending a new message
to the 1939STB.


MSGVAL Bits 6 and 7
Message Valid. The message must be valid before any operations can be
preformed on it. Messages can be preloaded on the converter and activated /
deactivated as needed. Note that all messages locations are set invalid at
power up. Any time the converter is reset, all message information is lost.


TXIE Bits 5 and 4
Transmit Interrupt Enable. Set bit(s) INTPND after a message is successfully
sent to the bus.

RXIE Bits 3 and 2
Receive Interrupt Enable. Set bit(s) INTPND after a message is received
from the bus. NOTE: It is possible to send a remote frame by setting both the
TXIE and RXIE. The controller will clear the TXIE after the message is sent
or if the data is received before the message can be sent.

INTPND Bits 1 and 0

Interrupt Pending. Indicates that a message object has generated an

interrupt request. Be aware that when a message is being serviced by the
controller, it is temporarily inactive. This prevents a message from being
overwritten by the J1939 controller while the message is being loaded to the
serial port. During the upload the message location cannot receive or
transmit.

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