5
NT511 AD ANALOG & DIGITAL INSIDE
TECSYSTEM SHANGHAI
7) CONNECTION WITH RS485 NETWORK
NT511 can be connected with a data acquiring device (PC, PLC, SCADA) for remote con-
trol. The used interface is RS485-type, which allows to connect 32 devices on the same line,
and it is based on Modbus RTU protocol.
In order to guarantee a proper network working, please follow what laid down by EIA RS485
standard which suggests to use a 24AWG duplex cable.
The duplex cable which connects all the units in RS485 could require a 120 ohm termination
on the last unit of the series.
Connect the duplex cable paying attention to the polarities and lay the network avoiding to
make sharp bends or ring windings in order not to modify the line impedance.
In case of particular noises, it could be necessary to ground the shielding on GND terminal.
8) TEMPERATURE SENSOR DIAGNOSTIC
8) TEMPERATURE SENSOR DIAGNOSTIC
In case of breaking of a temperature sensor mounted on the machine to be protected,
FAULT relay immediately switches with the relevant indication of the defective sensor on
the corresponding channel.
• Fcc for short-circuited sensor.
• Foc for interrupted sensor.
• Fcd temperature fast increasing (see pag.10).
To eliminate the message and reset Fault switching, it is necessary to verify Pt100 connec-
tions and, in case, replace the defective sensor.
Note: CAL message appears when it is determined the damage of the measuring circuit.
The temperature values shown could be incorrect. Please contact Tecsystem to return the
unit for repairing.
9) PROGRAMMED DATA DIAGNOSTIC
In case of breaking of the internal storage or corruption of programmed data, just after
switching on, the Ech wording is displayed with the relevant reporting of the Fault contact.
For safety reasons, in this case the default parameters Alarm Ch1-2-3= 90°C, Trip Ch1-2-3=
119°C, Ch4= Yes, Alarm Ch4= 120°C, Trip Ch4= 140°C, Ch-Fan= 1-2-3, Fan-on= 70°, Fan-
off= 60°, HFN= 000 are automatically loaded.
To remove Ech wording, press RESET and run programming to insert the desired values.
Finally turn off and turn on again the unit to verify the correct memory working; in case it is
damaged and the Ech wording is still displayed, please return the monitoring unit to Tecsys-
tem for repair).
10) TEMPERATURE DIAGNOSTIC
If one of the temperature sensor detects a temperature higher than 1°C compared to set
value as alarm limit, after approximately 5 seconds ALARM relay switches together with the
turning on of ALARM LED of the reference channel (CHn).
When the release temperature limit is passed, TRIP relay switches together with the turning
on of LED TRIP of the reference channel (CHn).
As soon as the taken temperature returns to equal or lower values than the set limit for
ALARM and TRIP relay switching, they de-energise with consequent turning off of relevant
LED’s.
