OTIS OI-6000K NXP Series, Руководство по эксплуатации

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PRODUCT SETTINGS AND CONFIGURATION
29 OI-6000K-X-X-X-NXP-X OPS_GUIDE_REV 1.0
3.9 MODBUS ADDRESS SETTING
Modbus is a leading industrial open control protocol. Modbus is available in several different types,
depending upon the media over which it is transmitted. Like most communication protocols, Modbus uses
a master/client type behavior. The master sends a poll request for information to the client, the client
decodes the request, and then sends a response with the requested data back to the master.
A Modbus message includes a Modbus address, commonly referred to as a unit ID. The Modbus address is
used to identify the server address in RS-485 networks. Each server is assigned an address and listens for
messages which contain this number in the Modbus address field.
The OI-6000K uses the original Modbus RTU specifications over the RS-485 link. RS-485 Modbus has 255
addresses, ranging from 1 to 255. Eight of the addresses are used for internal system settings, leaving
addresses 1 to 247 available for your device.
The RS-485 Modbus communication parameters used in Otis devices is 8 data bits, no parity, and 1 stop bit;
these parameters are fixed and cannot be changed. The floating point data values are presented with the
least significant bytes first.
When using Modbus over a RS-485 network, the communication parameters
MUST be set correctly for all
devices. For multiple devices using Modbus, ensure that no two units are assigned the same address. A
duplication of addresses could cause errors in the transmission of data. Modbus addresses can be assigned
sequentially or another appropriate address scheme for the specific network setup.
The factory default setting on the OI-6000K for the Modbus address setting is 1.
1. Use the ADD and SUB buttons to increase and decrease the Modbus address number, respectively.
2. Press the MENU button to select the desired setting and to advance to the Modbus baud setting screen.