how to design scada application for 3 devices.

[hamidshayesteh 0]

I'm a new user of Scada software, i want to create application with the below details, but i do not know,how? please help me. i have 3 devices that use MODbus protocol. these device send data through RS485 port to access point #1, then access point #2 receive data and send data to computer. scada software is install on this computer. i want to design scada application that show device's parameter on this computer and then send data to RTU. i have any question about this scada application, for example: channel type? number of channel? receive data protocol? send data protocol? how to break up these 3 device with single channel? and all thing that help me to design this scada application. Edited 21 Jul 2014 by hamidshayesteh

[mohssen 0]

Hi, I may suggest you a solution: You can use I-7513 module as a RS-485 Hub. The I-7513 is one channel RS-485 with a three way Active Star Wiring Hub. The unit has 3 independent RS485 output channels each with their own driver. You can communicate with all of your three devices at the same time. below Link: http://www.icpdas-usa.com/i_7513.html When you collect your data from three devices by I-7513, you can transfer them to your scada system using ZT-2551 which can be connected to RS-485 : http://www.icpdas-usa.com/zt_2551.html Please see below picture as well: https://imageshack.com/i/id1JviBQj Good Luck

[MrAutomation 20]

There's no need for an RS485 hub. RS485 is a multidrop protocol. You can configure it in a star from your modem/radio or, preferably, you can daisy chain them into a series loop, with an end of line resistor (120 ohms). Also that Zigbee device linked above has a whopping 700m range. I'm assuming that your application is much farther than 700m. You have a many choices for transfer medium, but here's a few recommendations. - Use a RS485 cellular Modem. There's a million options out there, here's an example. All you need is an internet connection on your SCADA computer and you can connect to the device. I recommend setting up a VLAN between the modem and the computer for security. - Use a radio network. This radio can be set up have either an ethernet or a serial radio link. If you use an ethernet radio link, you can still use the serial port on the radio, just like a modem. Ask sales/support for help with setting up either of the above mentioned devices. Nothing special is required to have all three RTUs on the same link, just make sure each unit has a unique Modbus Slave address. Hopefully this helps, best of luck!