Ametek Land 4500 MKIII, Руководство пользователя

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B - 11
Model 4500 MkIII Opacity and Dust Monitor
User Guide
B4.7 Setup Alarm
1) From Settings , press
2) Use the and arrows to select Alarm Type and press
3) Use the and arrows to select Opacity , Optical Density or
Dust Density and press
4) Use the and arrows to select Alarm and press
5) Use the and arrows to change the Alarm Level and press
6) Press to return to Settings
.
B4.8 Modbus Interface
Modbus communications, based on the RS485 duplex hardware standard,
provide direct access to the Model 4500 MkIII system data. Details of the
Modbus protocol are available from the Modbus website www.modbus.org.
The Model 4500 MkIII implements Functions: 1 (Read Coil), 3 (Read Holding
Register), 5 (Force Single Coil), 6 (Pre-set Single Register) and 10 (Pre-set
Multiple Registers)
Each Modbus must have one termination resistor at each end and one
bias network somewhere on the bus. The Model 4500 MkIII can provide a
termination resistor and a bias network. As supplied, the termination resistor
is switched on, and the bias network is switched off. To change these, switch
off the power, remove the rear cover from the Transceiver (see section E3),
and locate switch S1 on the Main printed circuit board. The four sections of
S1 have the following functions:
1 and 2
Bias network Supplied OFF
3 Not used
4 Termination resistor Supplied ON
The Model 4500 MkIII is shipped with the following default communications
settings:
Baud rate:
57600
Parity: Even
Data bits: 8
Stop bits: 1
Slave Address: 7