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GUIDELINES FOR RS-485 BUS CONNECTION 

RS-485 standard 

RS-485 standard is based on a balanced signals system. This means that two signals are ideally one opposed 
to each other, respect to the ground. 

It is strongly suggested that the transmission line will be formed by a “twisted pair” cable. This kind of cable 
is particularly immune to electromagnetic noise.  

 

 

Transmission cable 

In order to prevent any interference risks, a properly shielded cable should always be used, especially if you 
are close to power signals (e.g. electric engines, inverters, relais). 

We recommend to use cat. 5E cable or equivalent. 

Generally speaking, the RS-486 transmission cable should be shielded and compliant to the following 
specifications: 

 

Cable capacity <=300pF/m 

 

Line impedance 100 Ω ±15 Ω  

 

Line resistance 140 Ω/km or 225 Ω  

 

Cable type: copper twisted pair 

Network connection 

 

 

As far as possible, limit the RS-485 network to a main single line (one segment) 

 

Limit the total length of the main line to a maximum of 1000 m 

 

Do not connect more than 31 devices on the same RS-485 segment 

 

Disconnect the line termination resistors (if any) on all the slave devices connected 

 

For short networks (up to 30 m) no line termination resistor is needed 

 

For more extended networks, it could be necessary to terminate the RS-485 line in the 
following way: 

Summary of Contents for RILHEVA II

Page 1: ...1 RILHEVA II USERMANUAL V 1 5...

Page 2: ...ICE CONFIGURATION VIA SMS 14 DEVICE CONFIGURATION VIA WEB INTERFACE 16 PROCEDURE FOR FIRMVARE VERSION UNTIL RIL2_5 9 9 16 PROCEDURE FOR FIRMVARE VERSION RIL2_6 0 0 OR GREATER 17 STATUS PAGE 19 CONFIGU...

Page 3: ...7 Data addressing 27 Modbus functions 28 ACCESSORIES 28 GUIDELINES FOR RS 485 BUS CONNECTION 29 RS 485 standard 29 Transmission cable 29 Network connection 29 Configurations to avoid 30 Grounding 31 R...

Page 4: ...be installed inside an electric switchboard in order to make the clamps not accessible The switchboard wiring must be executed according to CEI regulations Do not power the device on while having any...

Page 5: ...and authenticate himself in order to monitor and control all the data available on the remote site in the same way as he was there The Rilheva II device implements internally the master Modbus protoco...

Page 6: ...6 SYSTEMARCHITECTURE...

Page 7: ...ndustrial plants PLC machinery facilities production lines Energy management energy analysis and business intelligence Remote reading consumption of distribution plants power lines pipelines aqueducts...

Page 8: ...8 DEVICEINSTALLATION Some installation examples follow...

Page 9: ...9...

Page 10: ...CTIONPORTS Ethernet port ETH1 Micro SD card Mini USB OTG port Serial connector 15 pin Antenna modem SMA F connector Diagnostic LEDs Digital input Power supply SIM card Ethernet port ETH0 USB port type...

Page 11: ...cess local devices on IP network Micro SD card This slot can host a micro SD card provided for future expansions related to backup or data export Mini USB OTG port Through this port implementing OTG U...

Page 12: ...ization 6 C 7 RS 485 A 8 9 TX RS 232 SERVICE diagnostics 10 RX 11 TX RS 232 A 12 RX 13 C COMMON GND 14 TX RS 232 B 15 RX Antenna modem SMA F connector A dual band GSM antenna omni or directional can b...

Page 13: ...ernet port that can be used as LAN in order to access local devices on IP network or WAN for internet connection USB port type A Through this port compliant to USB DEVICE standard it will be possible...

Page 14: ...to the SIM Cards 2 Power up the device After few seconds the 3 LEDs will blink at the same time indicating that the device is waiting for the first configuration e g configuration SMS message or web s...

Page 15: ...e device will reply to the sender with another SMS containing the following string CONFIGURAZIONE MEMORIZZATA DISPOSITIVO The connection settings will be repeated IMEI code cloud server host IP cloud...

Page 16: ...e click on the gear icon and select the Advanced tab PROCEDURE FOR FIRMVARE VERSION UNTIL RIL2_5 9 9 In order to configure the connection parameters of the Rilheva device please proceed as follows 1 C...

Page 17: ...figure a static IPv4 address within the subnet 192 168 44 x e g 192 168 44 10 and a subnet mask 255 255 255 0 3 Open your internet browser and point to the following address http 192 168 44 1 The auth...

Page 18: ...18...

Page 19: ...e main status information about Rilheva device In case of GPRS 3G connectivity the GSM signal will be shown Moreover it is present the firmware version and the network settings used for the Internet c...

Page 20: ...GPRS 3G section the APN parameter can be defined depending on the GSM operator chosen and username password only if required otherwise leave the field empty Using the Wan interface setting it is possi...

Page 21: ...21 DIAGNOSTICS PAGE This page offer some technical and diagnostic information useful to investigate and resolve possible bugs or abnormal behavior related to the Cloud connection...

Page 22: ...ONS Led STATUS solid orange If the STATUS led is solid orange an hardware error has occurred Please contact Technical Support Led STATUS blinking orange red alternately In this case the device is poll...

Page 23: ...ng the pinhole R pushed with a pin or paper clip waiting until the three LEDs will start blinking sequentially wait for about 20 seconds At this point just wait 5 seconds more until the led sequence w...

Page 24: ...ig bee GPS Expansion slot II proprietary slot for custom expansions Antenna external SMA MODEM 2G 3G optional WLAN GPS Case 6 modules DIN rail plastic case Onboard communication ports 4 serial ports 2...

Page 25: ...erial baudrate can be selected among 1200 bps 2400 bps 4800 bps 9600 bps 19200 bps 28800 bps 38400 bps 56000 bps 57600 bps 115200 bps The RTU byte is composed by 11 bit 1 start bit 8 data bit 1 parity...

Page 26: ...egister 1 Integer unsigned 0 65535 16 F4 Single register 1 Integer signed 32768 32767 16 F5 Couple of registers HI LO 1 Integer unsigned 0 4294967295 32 F6 Couple of registers HI LO 1 Integer signed 2...

Page 27: ...n be accessed by different access type Data addressing All the datatypes addressed by Modbus protocol registers and coils are zero based The first register of any kind has address 0 Every datatype can...

Page 28: ...g from a specified address 0x04 Read Input Registers reads one or more consecutive registers of INPUT type starting from a specified address 0x06 Write Single Register holding writes an HOLDING type r...

Page 29: ...s We recommend to use cat 5E cable or equivalent Generally speaking the RS 486 transmission cable should be shielded and compliant to the following specifications Cable capacity 300pF m Line impedance...

Page 30: ...daisy chain configuration This means that a single main line cable exists and all the devices are directly connected along the line path By using other kinds of connection e g star point T branching...

Page 31: ...g transmitting the RS 485 bus will remain in high impedance status In this situation sometime the RS 485 bus may be interfered by some external electromagnetic noise that could be interpreted as real...

Page 32: ...input impedance equal to 12K Two termination resistors 120 are present Supply voltage is 5 VDC We say Zo the impedance made by the parallel of 2 termination resistors 120 and 32 input impedance of th...

Page 33: ...33 ITEMSIZES...

Page 34: ...facturing fault o product quality must be notified in writing to XEO4 S r l by demonstrating that the product has been installed and maintained properly as described in the technical documentation att...

Page 35: ...35 Xeo4 s r l Via Asti 5 29121 Piacenza Italy Tel 0523 498721 Fax 0523 401738 support xeo4 it info xeo4 it www xeo4 it...

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