Manual NOVOS und thanos EVO
Thermokon Sensortechnik GmbH
Seite
7
3
Assembly and commissioning
Proper commissioning ensures a seamless and safe use of the devices. Please observe the instructions in the corresponding data sheet.
3.1
Connection
3.1.1
RS485 Wiring
The maximum cable length per line should not exceed 1,200 meters. The last device in a line must be terminated with a 120 Ohm resistor to avoid
signal reflections from the BUS. Please make sure, that both resistors are properly connected to the terminals. The MODBUS specification requires
the use of terminating resistors (120 - 150 Ohm, 0.25 W) at both ends. The terminating resistor is not included in the delivery of the devices.
The room operating units load the BUS with a standard BUS load (1/1 unit load according to the RS485 standard). This allows up to 32 room operating
units to be operated on one single BUS line.
Please also note that RS485 does NOT support star topologies and no stub line connection!
If no signals are present on the BUS, it must be ensured that the signal levels (voltage) are fixed. This can be done through pull-up / pull-down
resistors on the drivers. These form a voltage divider with the installed BUS termination resistors. It must be ensured, that there is at least a
differential voltage of 200mV detectable for the receiver between the data lines A and B.
3.1.2
Operation with alternating voltage power supply (AC)
If several field devices are supplied from one AC voltage source according to the specification, it is mandatory, that all "positive" operating voltage
inputs (+) of the field devices are connected to each other, and all "negative" operating voltage inputs (-) = reference potential are connected to
each other (series connection of the field devices).
If the polarity of the supply voltage is reversed on one of the field devices, a short circuit of the supply voltage would occur. The short-circuit current
thus flowing through this field device leads to a damage of this device.
Pay attention to a correct wiring!
3.1.3
Electrical connection
Connect the power supply and the RS485 lines according to the wiring diagram. Power must be supplied from sources that meet the requirements
for protective low voltage. After switching on the power supply, the device starts up.
3.2
RS485 BUS Configuration
Each device that communicates through Modbus is assigned a unique address. In serial networks, only the node assigned as the Master may execute a
command. The BUS interface can be parameterized by means of the NOVOSapp or using the onboard screen configuration menu.
NOVOS 7
NOVOS Touch / thanos EVO
Bus address
1-247 (Address 1 – factory default)
1/1 Bus load per device,
corresponds to 32 participants per segment
Baud rate
9600
19200
38400
57600
76800
115200
(factory default)
4800
9600
14400
19200
38400
56000
57600
76800
115200
(factory default)
Parity and stop bit
Even
Odd
None, 1 Stop bit
None, 2 Stop bits
(factory default)
|
__
DI
Digital Input
(für potentialfreien Kontakt → GND)
|
__
B-
____________
BUS B
|
__
B-
____________
BUS B
|
__
A+
____________
BUS A
|
__
A+
____________
BUS A
|
__
GND
_________
0 V
⏊
|
__
UB+
__________
24 V
⎓
(±10%) / 24 V
∿
(±10%) SELV
