MERRICK MC3 90.10.EX, Руководство по эксплуатации и техническому обслуживанию

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MC³ 90.10.EX O&M Manual - 23 -
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Data Bits
The number of data bits value indicates how many bits represent each character transmitted or
received on the serial communications lines. The options available are 5, 6, 7 or 8. The
recommended value is eight (8).
Stop Bits
This value is used to number of stop bits added to the end of a character transmission unit and
may be set to 1 or 2. The recommended value is one (1).
Parity
Parity is a method of error checking during serial communications. Available selections:
NONE ODD EVEN MARK SPACE
Comm 1 Numeric
An ASCII Begin Code and End Code must be designated for each message sent to and from the
serial port on the MC³ Controller. Since not all computers and protocols have the same Begin
and End Codes, an operator may wish to change them in order to attempt to communicate with
non-Merrick equipment. A specific controller number is used to identify each controller on the
network.
NOTE: Power must be cycled to this controller for changes to communication parameters to take
effect.
NOTE: It is very important: Two (2) controllers on the same serial line do not have the same controller
address! This would result in both responding to a message at the same time. The results
would usually be unusable data.
Comp Start Code
This value is always sent at the beginning of a communications message. This default value is
10, for an ASCII representation of a Line Feed. To enter new values for this variable, use the
arrow keys to select you choice. Limits are minimum of 1 and a maximum of 127.
Comp End Code
This value is always sent at the end of a communications message. This default value is 13, for
an ASCII representation of a Carriage Return. Limits are minimum of 1 and a maximum of 127.
Controller Number
This number is used to identify the numeric address of the controller when utilizing serial
communications on a multi-drop line. Controllers connected to the same communication line
should not have the same controller number. Limits are minimum of 1 and a maximum of 64.
Com Protocol
This parameter selects the communications protocol used on Comm Port 2.
0 Scalenet
1 Modbus ASCII
2 Modbus RTU
Communication Time-out
This parameter is the allowed limit of no communications activity on the serial port. If this value is
exceeded, the logical output Comm Timeout will turn on.
Write Enable
The controller will not write a value to a register until the bit for the register in this word is set.
See the Modbus protocol manual for the correct bit order.
Byte (Word) Order
The Byte (Word) order bit reverses the order of the two (2) words that contain the value
information. This may be needed to allow the device requesting the data to receive the value in
the format it needs to correctly process the data.