5 Installation at Site
29 of 68
Calio
1157.821/04-EN
Parameter
Description/value
Bus connection
0.5 mm
2
, shielded twisted pair bus cable
Cable length
▪
1000 m max.
▪
Stub line impermissible
▪
For cable lengths > 30 m take suitable measures to ensure overvoltage
protection.
Wave impedance
120 Ω (cable type B to TIA-485-A)
Data rates [baud]
4800, 9600, 38,400, 57,600, 115,200
(19,200 = factory setting)
Protocol
Modbus RTU standard
Data format
▪
8 data bits
▪
Parity EVEN / ODD / NONE
▪
1 stop bit
Modbus address
ID #1 to #247 selectable
(ID #17 = factory setting)
ü
The mains voltage at the site has been verified against the data on the name
plate.
ü
The pump set has been de-energised and secured against unintentional start-up.
ü
The wiring diagram is on hand.
1. Unscrew the cable glands (IPX4D).
2. Undo and store the 2 screws of the cover of the terminal wiring compartment.
3. Remove the cover of the terminal wiring compartment.
4. Knock out and remove the closing disc of the required cable gland with a
suitable tool (e.g. screwdriver).
5. Wire a suitable bus cable to the terminal pair of the three-piece Modbus
terminal and connect it to earth.
ð
The terminals are suitable for a core cross-section of up to 1.5 mm
2
.
6. Fit the cover of the terminal wiring compartment. Fasten it with the 2 screws.
7. Tighten the cable glands (IPX4D).
Connection to the Modbus master
Connect all pump sets to a Modbus master. The Modbus master controls the bus
communication and sends telegrams to the connected pump sets. All pump sets are
slaves and only respond to the Modbus master. The pump sets do not send telegrams
by themselves. Each pump set is assigned its own unique address at the time of
commissioning.
Use a Modbus network cable or a cable with a defined wave impedance (e.g.
Ethernet cable) to prevent signal losses in the electric cable. System-specific signal
losses occur, for example, in the event of a failure of communication between
Modbus master and pump set.
1. Remove the cover of the terminal wiring compartment.
2. Connect a suitable Modbus network cable to terminals D+ and D- of the three-
piece Modbus terminal.
3. The earthing terminal is connected to earth at the pump. The shield of the bus
cable can be connected to this terminal, for example. The terminals are suitable
for a core cross-section of up to 1.5 mm
2
.
Terminating the Modbus data line (hardware)
Terminate either end of the Modbus network cable with a 120 Ω resistor. Enable
both DIP switches for this purpose.
The wave impedance of the Modbus network cable used corresponds to the
terminating resistor.
