7.1.3 Bus Termination
Use the terminator DIP switch on the main control board
of the unit to terminate the RS485 bus.
NOTICE
The factory setting for the switch is OFF.
68
69
N (-)
RS485
RS485
P (+)
175ZA907.10
Illustration 7.2 Terminator Switch Factory Setting
7.1.4 EMC Precautions
The following EMC precautions are recommended in order
to achieve interference-free operation of the RS485
network.
•
Observe relevant national and local regulations
regarding protective ground connection.
•
Keep the RS485 communication cable away from
noisy cables such as power lines and motor
cables. Doing so reduces high frequency noise
transference. A distance of 200 mm (8 in) is the
minimum, but keeping the greatest possible
distance between cables is best, especially when
cables run in parallel over long distances.
•
When crossing cables is unavoidable, the RS485
cable must cross other power cables at a 90
°
angle
7.2 Network Configuration
Set the parameters in
Table 7.2
to enable the FC protocol
for the filter.
Parameter Number
Setting
Parameter 8-30 Protocol
FC
8-31 Address
1-126
Parameter 8-32 FC Port
Baud Rate
2400-115200
8-33 Parity / Stop Bits
Even parity, 1 stop bit (default)
Table 7.2 Configuration Parameter Settings
7.3 FC Protocol Message Framing Structure
7.3.1 Content of a Character (byte)
Each character transferred begins with a start bit. Then 8
data bits are transferred, corresponding to a byte. Each
character is secured via a parity bit. This bit is set at 1
when it reaches parity. Parity is when there is an equal
number of 1s in the 8 data bits and the parity bit in total.
A stop bit completes a character, thus consisting of 11 bits
in all.
0
1
3
2
4
5
6
7
195NA036.10
Start
bit
Even Stop
Parity bit
Illustration 7.3 Content of a Character
7.3.2 Telegram Structure
Each telegram begins with a start character (STX)=02 hex,
followed by a byte denoting the telegram length (LGE) and
a byte denoting the filter address (ADR). A number of data
bytes (variable, depending on the type of telegram)
follows. The telegram is completed by a data control byte
(BCC).
STX
LGE
ADR
DATA
BCC
195NA099.10
Illustration 7.4 Telegram Structure
RS485 Installation and Set-...
Operating Instructions
70
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