
2.4 Serial Communication Interfaces (For Models with RS485 Port)
The iLD Big Display controller/monitor with the Embedded Ethernet Server option board support only RS485/422 interfaces. These standards define the electrical characteristics of a communication network. The RS485 port of the Ethernet Server is fully compatible for use with RS422 instruments. The RS485 is an extended version of the RS422 communication standard which increases the allowable number of devices from 10 to 32 by improving the electrical characteristics.
•The RS485 standard
Although the RS485 is commonly referred to as a "two wire" connection, the Web Server also provides a ground/return shield connection to use as a common connection for EMI noise protection.
Table 2.2 shows some characteristics of the RS485 communication interface.
Table 2.2 Data Transmission Characteristics RS485
Data Transmission Characteristics | RS485 | |
Transmission Mode | Differential |
|
Electrical connections | 2 wire |
|
Drivers per line | 32 drivers |
|
Receivers per line | 32 receiver |
|
Maximum data rate | 10M bits/s |
|
Maximum cable length | 4000 ft (1200 meters) |
|
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