Parker NITROSource N2-20P, User Manual

Page: 19 / 32

17 - EN
3.6.6 4–20mA Analogue Output
The oxygen content detected by the generators internal analyser may be re-transmitted to external peripherals using the 4-20mA linear analogue
output. The output is a linear current source, with 10 bit resolution, which increases from 4mA (Zero Oxygen) to 20mA (Full Scale Deflection). The
FSD of the internal analyser is factory set to a default value of twice the generators specified purity. For % purity generators the maximum FSD is
set to 6%. The oxygen purity setting of the generator is marked on the rating plate. The table below shows the correlation between the purity
settings of the generator and the output current.
It is recommended that the cable used for the 4-20mA Analogue Output is screened twisted pair. Ferrites should be added to the cable, using 1
turn, either side of the shroud cable gland. It is recommended that the cable used does not exceed 30m in length. Suitable ferrites are available
from Wurth Electronics (P/N. 74271633S).
3.6.7 MODBUS
The generator’s controller is capable of supporting direct Modbus communication via its integral RS485 connection. This industry standard
connection allows multiple generators to communicate with a remote Modbus master on a network up to 30m in length. The generator can be
programmed with its own unique address, to allow multiple generators to be connected to an existing network.
Terminals Description Cable size
Analyser - #6
Positive
3 - 7mm
Analyser - #7
Negative
Generator
Purity
Full Scale Deflection
Resolution
4mA - 20mA
5ppm 0 - 10ppm 1ppm = 1.6mA
10ppm 0 - 20ppm 1ppm = 0.8mA
50ppm 0 - 100ppm 1ppm = 0.16mA
100ppm 0 - 200ppm 1ppm = 0.08mA
250ppm 0 - 500ppm 1ppm = 0.032mA
500ppm 0 - 1000ppm 1ppm = 0.016mA
0.1% 0 - 0.2% 0.01% = 0.8mA
0.4% 0 - 0.8% 0.01% = 0.2mA
0.5% 0 - 1% 0.01% = 0.16mA
1% 0 - 2% 0.01% = 0.08mA
2% 0 - 4% 0.01% = 0.04mA
3% 0 - 6% 0.01% = 0.026mA
4% 0 - 6% 0.01% = 0.026mA
5% 0 - 6% 0.01% = 0.026mA
Terminals Description Cable size
RS485 MODBUS - A
For MODBUS communication setup details refer to dh
publication 176500120
3 - 7mm
RS485 MODBUS - A