E.1.3 Set Up Procedure - Honeywell CM4 Technical Handbook

CM4 Four-Point Continuous Monitor

E.1.3 Set up Procedure

After the networking cabling has been connected to the slave, the
slave must be configured to communicate. Baud rate, address, and
protocol version are selectable. Configuration is performed with the
following sequence:
<PROGRAM> <1> is pressed to stop monitoring.
SELECT PROGRAM < >
The keys 3 3 1 are pressed to go to the COM port setup menu.
SET COM PORT
One of the four protocol configurations must be selected.
COM PORT DISABLED
COM PROT VER 1
COM PROT VER 2
COM PROT LONWORKS
Protocol 1 is recommended for compatibility with existing master
computers. Protocol 2 provides superior data integrity, but requires
a change to the master. LONWORKS requires extra hardware. The
selection is made by pressing <ENTER>.
COM PORT 9600 BAUD
Baud rates of 1200, 2400, 4800, 9600, and 19200 are available. 9600
baud is recommended for most applications. The selection is made
by pressing <ENTER>.
SET INST. ADDRESS
INST. ADDRESS 001
CM4 Technical Manual
or
or
or
Every slave on a network must have a unique address from 1 to
255. If only one slave is present, this value may remain at 1. After
entering a unique number, press <ENTER>.
After these steps the COM port setup is complete. Normal operation
is restored by pressing <MONITOR>.
E.1.4 Protocol Specifics
The protocol has been designed for flexibility and efficiency.
This byte-wise protocol communicates information by transferring
bytes of data back and forth between master and slave. A group of
bytes for each communication is called a packet.
The master and slave(s) transfer information via data packets. These
packets will always contain bytes to start communication, an address,
a packet length, a command, and a checksum.
Additional optional variable-length data bytes or optional parameters
can also be sent or received. This section is a brief overview of the
protocol specifics
Data and Packets
A byte is a piece of data. It is a way to indicate information and is
composed of eight bits of information. A bit is the smallest possible
piece of information. It can only be two possible values, 1 or 0
(True or False). A byte can have a decimal value from 0 to 255. In
hexadecimal representation, a byte's value can range from 0x00 to
0xFF. Hexadecimal representation will be used for the remainder of
this manual. The number may be interpreted in a manner other than
a number, for example, as a letter.
Using ASCII characters, where 0x41 is the letter A, 0x42 is the letter B,
0x43 is C, and so on, a message can be written as these numbers. Each
number is a byte. For example, the word "BAD" is 0x42, 0x41, 0x44.
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