Table 8 Serial Port S1/S2 Settings (Right Side Of Display) - Honeywell 900 User Manual

Serial Port S1/S2
Setting
Protocol
Baud Rate (Bps)
Modbus Parity
Modbus Stop Bits
Slave Address (1-247 or
255)
Slave Port Enable
Double Register Format
Revision 9
May 2014

Table 8 Serial Port S1/S2 Settings (right side of display)

ELN: The default protocol, used to communicate with the HC Designer
configuration software.
MODBUS MASTER: The controller acts as a Modbus Master device on the
communication link.
MB MASTER ADVANCED: The controller acts as a Modbus Master device on the
communication link. This protocol provides enhanced data throughput for
applications where the HC900 is being used with a "Modbus-to-fieldbus" gateway
device.
MODBUS SLAVE MULTI: The controller acts as a Modbus Slave device. This
protocol allows more than one slave device to be present on the communications
link (multi-drop).
MODBUS SLAVE PTP: The controller acts as a Modbus Slave device. This
protocol can be used if the controller is the only slave device on the link (Point-to-
point).
MODBUS SLAVE MODEM: The controller acts as a Modbus Slave device. This
protocol provides the extended delays that are needed to access the controller via
a modem.
Select 9600, 19200, 38400, 57600 or 115200 bits per second.
Select None, Odd, or Even parity.
Select 1 or 2 Stop Bits.
This is the address of the controller on the Modbus link when one of the three
Modbus Slave protocols is selected. All devices on the link must have a unique
Modbus address. The address may be set to a value of 1 to 247, or it may be set
to 255. A value of 255 disables the port for this controller.
This item allows you to enable or disable the port:
ENABLE: The port will respond to communication requests.
DISABLE: The port will ignore communication requests.
Under the Modbus protocol, each IEEE 32-bit floating-point number requires two
consecutive Modbus registers, for a total of four bytes. The stuffing order of the
bytes within these registers differs among Modbus devices. To provide
compatibility with the various hosts, the double-register format is configurable. The
selections are:
FP B Big Endian format
FP L Little Endian format
FP BB Big Endian with byte-swap
FP LB Little Endian with byte-swap
900 Control Station User Guide
Description
Byte order: 4, 3, 2, 1
Byte order: 1, 2, 3, 4
Byte order: 3, 4, 1, 2
Byte order: 2, 1, 4, 3
Main Menu
Communications
25