HORNER HE800JCM200, Руководство пользователя

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CH. 1 14 MAY 2002 PAGE 7
MAN0484-01
CHAPTER 1: INTRODUCTION
1.1 Overview
The HE800JCM200 is a SmartStack SAE J1939 Communication Module. SAE J1939 (J1939) is a CAN-
based protocol used in truck and bus control communications networks. There are various layers to the
J1939 protocol that are described in SAE J1939 documents. J1939 uses a 29-bit identifier requiring
hardware that can support CAN 2.0B. The address for the JCM200 is fixed at 251. The baud rate is fixed
at 250Kbps. SAE J1939 specifies a table of Parameter Group Numbers (PGNs). A PGN is unique
numeric identifier that is associated with a specific parameter name. A PGN is used to define the
parameter value a device is requesting or the parameter value that a device is sending.
Note: SAE is an acronym for
Society of Automotive Engineers.
1.2 Product Description
There are 2 operational bi-colored LEDs on the side of the module. One LED is green indicating the
module is OK. The other LED flashes orange, indicating network traffic.
1.3 Functional Description
The JCM200 can request/monitor data from and transmit data to devices on the J1939 network. There
are two communication methods used for handling data:
Scanning and Transmit Channel. For detailed
information, refer to Chapter 2: Operation.