The Modbus Protocol Handling - Level Pro ITC 450 User Manual

ITC 450/470
User manual
Calculated Iout do not exceeds the output working range (3.8 - 21 mA).
b) D = „20.5"
According to formula from page 34:
I = (20.5-10.0) / (20.0-10.0) × 16 mA + 4 mA = 1.05 ·16 + 4 = 20.08 mA
out
Calculated Iout do not exceeds the output working range (3.8 - 21 mA).
c) D = „30.0"
According to formula from page 34:
I = (30.0-10.0) / (20.0-10.0) × 16 mA + 4 mA = 2 ·16 + 4 = 36 mA.
out
Calculated Iout exceeds the output working range (3 - 21 mA), so current output will generate
current equal to the upper border of range defined by parameter "Lo r" i "Hi r" (it means 21 mA).
11. THE MODBUS PRO TOCOL HANDLING
Transmission parameters : 1 start bit, 8 data bits, 1 or 2 stop bit (2 bits are send, 1 and 2 bits are accepted
Baud rate :
Transmission protocol :
The device parameters and display value are available via RS-485 interface, as HOLDINGtype registers
(numeric values are given in U2 code) of Modbus RTU protocol. The registers (or groups of the registers) can
be read by 03h function, and wrote by 06h (single registers) or 10h (group of the registers) accordingly to
Modbus RTU specification. Maximum group size for 03h and 10h functions can not exceeds 16 registers (for
single frame).
The device interprets the broadcast messages, but then do not sends the answers.
when receive), no parity control
selectable from: 1200 to 115200 bits/second
MODBUS RTU compatible
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