kmtronic W8CR Relay Controller
Specifications:
- Number of Relays: 8
- Rated voltage: 9 – 24V DC
- Relay switching power: 15A/24VDC (125VAC), 10A/250VAC
- Communication: LAN Interface
- Dimension: 149mm x 110mm x 25mm (connectors mounted)
Product Usage Instructions
Connection Details
A basic connection diagram is provided for both AC and DC loads.
Ensure to use a freewheeling diode or snubber circuit for inductive loads. Use wires rated to handle load current and exercise caution with high voltages to prevent damage to the module and PC.
Relay Contacts
OFF State: Close connection between NC and C,Open connection between NO and C.
ON State: Open connection between NC and C,Close connection between NO and C.
DC Power Supply
The board requires a power supply of 9 to 24V DC for proper functioning. Use a 9 to 24V DC / 500mA or higher power supply, ensuring correct polarity when connecting. Attach the positive terminal to the + terminal on the module.
Operation Requirements
The product is compatible with any operating system with a web browser and can be controlled via TCP/IP using various programming languages mentioned earlier.
How to Use WEB Eight Relay?
Connection Details
Refer to the provided connection diagram for both AC and DC loads. Use appropriate precautions when dealing with high voltages.
CONNECTING AND OPERATION
Security and Handling
Safety Instructions:
This device may connect to LAN port of your computer or router and can be used to control external devices connected to its onboard relays. Incorrect wiring or shorts on the board can potentially cause damage to the controller itself, your computer’s LAN controller and/or your computer’s motherboard if an external voltage make its way to the LAN interface. Extreme care must be taken when using this device to avoid any damage to your equipment. In particular, make sure you always disconnect the
device from the LAN port as well as any other power source when working on the device.
KMTronic, its shareholder, employees, suppliers, distributors and/or resellers are not liable for any damage or loss of data as a result of the use of this device, including special, incidental, or consequential damages resulting from the use of this device, or under any legal theory, including lost profits, downtime, goodwill, damage to or replacement of equipment or property, and any costs or recovering or reproducing any data stored in computers connected to this device.
Your use of this circuit indicates your acceptance of these terms
An Overview
KMTronic WEB Eight Relay is a versatile product for controlling electrical and electronic devices remotely via web browser. Ease of use and wider operating system compatibility are the primary goals behind the product’s design. The simplicity of connection and settings allows user to control and manage relays via web browser. For power users, this module can be controlled by writing programs in various programming languages and controlled via TCP/IP protocol.
Some of possible uses of the module include
- Home Automation
- Lighting Control
- Garden Equipment Control
- Industrial Automation
- Test Fixtures
- DIY and Hobby
And these are some of the languages that can be used for programming
- C/C++/C#
- Visual Basic (VB6, VB2008, VB2010 express and other editions)
- Visual Basic for Applications (Microsoft Office VBA)
- Perl
- Python
- Java
- And many more…
Specification
- Number of Relays: 8
- Rated voltage: 9 -24V DC
- Relay switching power: 15A/24VDC(125VAC) 10A/250VAC
- Communication: LAN Interface
- Dimension : 149mm x 110mm x 25mm (connectors mounted)
Package Contents
The following is included in the WEB Eight Relay package
- WEB Eight Relay board
Operation Requirements
This product is compatible with the following operating systems
- Every OS with available web browser
- Programs over TCP/IP, built with mention above programming languages
How to use WEB Eight Relay
Connection Details
Above image shows basic connection diagram that can be used in most of the situations. The connection diagram is same for both AC and DC loads. Please make sure to use a freewheeling diode or snubber circuit if the load is inductive. More details about using inductive loads is available elsewhere in this document. It is important to make sure that the wires used to connect loads are sufficiently rated to handle expected load current. Exercise caution while working with high voltages. Short circuits can cause damage to the module and the PC. The following sections identify individual connections in detail.
IMPORTANT NOTE
This circuit involves high voltage AC main power wiring when used to control high voltage AC devices. Please note that handling, testing and operating high voltage AC powered equipment can be dangerous and fatal when basic safety rules are note followed. ALWAYS disconnect the circuit from the AC line prior to performing any work on the circuit.
If you are inexperienced or not confident in working with high voltage AC powered circuits, we strongly recommend that you DO NOT attempt to use this circuit and seek help of a licensed electrician.
Relay Contacts
All contacts on each relay are available externally on screw terminals for easy user access. The relays are rated for AC and DC supply voltages. Please see the electrical parameter table for more details. Each relay has three contacts (C,NO and NC). C is the common terminal and is used in both normally open and normally closed positions. The contacts NC and C will be connected when the relay is turned off and will be disconnected when relay is turned on. And vice versa, the contacts C and NO will be disconnected when relay is turned off and will be connected when the relay is turned on. Table below summarizes possible relay contact
| Relay State | Connection between NC and C | Connection between NO and C |
| OFF | Close | Open |
| ON | Open | Close |
DC Power Supply
This board need power supply from 9 to 24V DC for function properly. The power supply for the boards is not optional and the relay will not switch without this supply. Any off the shelf 9 to 24V DC /500mA or more power supply can be used for this purpose. Make sure to connect the power supply in correct polarity. Connect the positive terminal of the power supply to the + terminal on the module. Connect negative terminal of the power supply to – terminal of the module.
Installation
Default settings:
- IP address: 192.168.1.199
- Subnet Mask: 255.255.255.0
- Default Gateway: 192.168.1.1
- Username: admin
- Password: admin
Reset defaults settings:
Hold Reset button for 10 seconds
- Connect power and LAN cable to router. Open your favorite browser and type: 192.168.1.199.
If explorer opens new window with request for USER and PASSWORD, enter default Username and Password. That’s all and you are ready to control and manage relays. If you cannot open default IP address, follow next: - Check that IP your router LAN is 192.168.1.1: http://kmtronic.com/how-to-find-your-local-ip-address.html
If LAN IP, your router is different than 192.168.1.1 (192.168.0.1 or 192.168.10.1) you need one time access to network 192.168.1.1 to change default settings. - Open again the web browser and type: 192.168.1.199.
The following images show the first steps of installing board. By clicking relay buttons you control them – switch on and switch off. In Configuration you can change default relay and network settings.
Authorization Configuration allows to change default Username and Password.
List of command set
Controlling of the relays is also available with set of ASCII commands which can be send via web browser (added after the IP of the board – for example http://192.168.1.199/FF0101) or with appropriate program over TCP/IP. The table below contains available commands for WEB and UPD:
WEB Control:
| No. | Command | Format | Description |
| 1 | /relays.cgi?relay=1 | ASCII | Toggle relay 1 |
| 2 | /relays.cgi?relay=2 | ASCII | Toggle relay 2 |
| 3 | /relays.cgi?relay=3 | ASCII | Toggle relay 3 |
| 4 | /relays.cgi?relay=4 | ASCII | Toggle relay 4 |
| 5 | /relays.cgi?relay=5 | ASCII | Toggle relay 5 |
| 6 | /relays.cgi?relay=6 | ASCII | Toggle relay 6 |
| 7 | /relays.cgi?relay=7 | ASCII | Toggle relay 7 |
| 8 | /relays.cgi?relay=8 | ASCII | Toggle relay 8 |
| 9 | /FF0101 | ASCII | Turn ON relay 1 |
| 10 | /FF0201 | ASCII | Turn ON relay 2 |
| 11 | /FF0301 | ASCII | Turn ON relay 3 |
| 12 | /FF0401 | ASCII | Turn ON relay 4 |
| 13 | /FF0501 | ASCII | Turn ON relay 5 |
| 14 | /FF0601 | ASCII | Turn ON relay 6 |
| 15 | /FF0701 | ASCII | Turn ON relay 7 |
| 16 | /FF0801 | ASCII | Turn ON relay 8 |
| 17 | /FF0100 | ASCII | Turn OFF relay 1 |
| 18 | /FF0200 | ASCII | Turn OFF relay 2 |
| 19 | /FF0300 | ASCII | Turn OFF relay 3 |
| 20 | /FF0400 | ASCII | Turn OFF relay 4 |
| 21 | /FF0500 | ASCII | Turn OFF relay 5 |
| 22 | /FF0600 | ASCII | Turn OFF relay 6 |
| 23 | /FF0700 | ASCII | Turn OFF relay 7 |
| 24 | /FF0800 | ASCII | Turn OFF relay 8 |
| 25 | /FFE0xx | ASCII | xx – HEX representation of relays state
MSB – relay8 LSB – relay1 Example: xx = A6; //0xA6 HEX 0xA6 as binary: 10100110
|
UDP Control:
| No. | Command | Format | Description |
| 1 | FF0101 | ASCII | Turn ON relay 1 |
| 2 | FF0201 | ASCII | Turn ON relay 2 |
| 3 | FF0301 | ASCII | Turn ON relay 3 |
| 4 | FF0401 | ASCII | Turn ON relay 4 |
| 5 | FF0501 | ASCII | Turn ON relay 5 |
| 6 | FF0601 | ASCII | Turn ON relay 6 |
| 7 | FF0701 | ASCII | Turn ON relay 7 |
| 8 | FF0801 | ASCII | Turn ON relay 8 |
| 9 | FF0100 | ASCII | Turn OFF relay 1 |
| 10 | FF0200 | ASCII | Turn OFF relay 2 |
| 11 | FF0300 | ASCII | Turn OFF relay 3 |
| 12 | FF0400 | ASCII | Turn OFF relay 4 |
| 13 | FF0500 | ASCII | Turn OFF relay 5 |
| 14 | FF0600 | ASCII | Turn OFF relay 6 |
| 15 | FF0700 | ASCII | Turn OFF relay 7 |
| 16 | FF0800 | ASCII | Turn OFF relay 8 |
| 17 | FFE0xx | ASCII | xx – HEX representation of relays state MSB – relay8
LSB – relay1 Example: xx = A6; //0xA6 HEX 0xA6 as binary: 10100110 |
| 18 | FF0000 | ASCII | Return Status of Relays – xxxxxxxx First digit(MSB) is status of Relay1, last(LSB) – status of Relay8
Example: Board returns in ASCII 10100110 |
UDP test software (including source code) can be downloaded from here: https://www.kmtronic.com/LAN-Relay-Controllers/UDP-LAN-Ethernet-IP-Eight-channels-Relay-Controller.html
Additional information
Handle inductive loads
General-purpose relays are typically designed to drive resistive loads, not inductive loads.
This is why electromechanical life ratings are published for resistive loads and not inductive loads.
Inductive loads can best be defined as anything with a magnetic coil, such as a motor, solenoid, or a transformer. The purpose of this capacitor is to absorb the high voltages generated by inductive loads. Unlike resistive loads, inductive loads love power, and they will do everything they can to hold on to it. The unpleasant result of this power hunger is inductive kickback, and it has a devastating effect on the contact life of most general-purpose relays. This is true of both ac and dc inductive loads, although the inductive kickback is far worse with dc loads due to the constant current characteristic of dc power. How bad is the kickback? A 24-Vdc solenoid with a current consumption as low as a quarter of an amp will create a negative inductive kickback of more than 300 V.
Adding a suspension capacitor could easily reduce the problems. It has to be installed as close as possible to the Relay Board.
DME Polyester Film Capacitors are suitable for this job with capacitance around 0.47uF – 0,68uF will be satisfied.
Choose larger voltage rating than your power supply.
Search it at digikey.com –
http://www.digikey.com/scripts/dksearch/dksus.dll?FV=ffec2aa9%2Cfff40002%2Cfff80010%2Ce340003&k=Polyester+Film+Capacitor&vendor=0&mnonly=0&newproducts=0&ptm=0&fid=0&quantity=0&PV13=46&PV13=47&PV13=49
If you can’t find it, you can use other Metalized Polyester Film Capacitor.
Technical specifications
| Parameter * | Value | Unit |
| Basic Specification | ||
| Number of relays | 8 | |
| Digital circuit power supply voltage | 9 – 24 | V |
| Standby current at 12V | 100 | mA |
| Maximum current drawn by digital circuitry at 9V | 500 | mA |
| Maximum current drawn by digital circuitry at 12V | 370 | mA |
| Maximum current drawn by digital circuitry at 24V | 200 | mA |
| Relay Specifications | ||
| Nominal relay coil voltage | 5 | V |
| Nominal coil power consumption (per relay) | 360 | mW |
| Relay contact material | Ag alloy | |
| Contact rating | AC125V 15A AC250V 10A
DC24V 15A |
|
| Maximum switching voltage | AC 240V DC 110V | |
| Maximum switching current | 20 | A |
| Maximum switching power | 2500VA | |
| Contact resistance (initial) | 50 | mΩ |
| Life expectancy (Electrical) | 100,000 ops | |
| Life expectancy (Mechanical) | 10,000,000 ops | |
| Nominal insulation resistance | 100MΩ (DC500V) | |
| Maximum switching on response time | 10 | ms |
| Maximum switching off response time | 5 | ms |
All parameters considered nominal. KMTronic LTD reserves the right to modify products without notice.
Physical Dimensions
Standard board
DIN mounting
Other information
You can find test software and programs, as well as additional information at: http://www.kmtronic.com/
Manufacture by:
KMTronic LTD
Bulgaria
FAQs
Q: What are some possible uses of the KMTronic WEB Eight Relay module?
A: Some possible uses include Home Automation, Lighting Control, Garden Equipment Control, Industrial Automation, Test Fixtures, DIY, and Hobby projects.
Q: What are the specifications of the KMTronic WEB Eight Relay module?
A: The module has 8 relays, a rated voltage of 9-24V DC, relay switching power of 15A/24VDC (125VAC) 10A/250VAC, LAN Interface communication, and dimensions of 149mm x 110mm x 25mm (with connectors mounted).
Documents / Resources
 |
kmtronic W8CR Relay Controller [pdf] User Guide W8CR, W8CR Relay Controller, W8CR, Relay Controller, Controller |
