Monday, January 27, 2014

Connecting the ComAp Generator Control Panel to the Netbiter

In this blog, I will discuss the steps involved in getting the Netbiter to record and display values coming out of the ComAp Generator Panel, so that one can do remote monitoring and control of the generator. The Netbiter Model used in this case is the EC220 and the panel used is the InteliLite AMF 26 P. The steps followed here can be applied to any MODBUS device due to the generic  nature of the Netbiter. 

Step 1 - Physical Connection 
Check that the Control Panel has a communication module attached to the back of it. You will need to establish the medium (RS458/RS232) and the protocol spoken (MODBUS RTU/ASCII) - all of this information will come from the user manual of the generator. Finally confirm the communication settings (baud rate, parity, stop bits, etc) - these can sometimes be changed so check what they are on the actual panel. In this case, we have the following settings:
  • MOUBUS RTU over RS232 (you'll need an external converter to convert the RS232 to RS485). 
  • Baud rate: 9600bps, 1 start bit, 8 data bits, 2 stop bits. (since we have 2 stop bits, we do not have parity checking)
Tip! Make sure that the RS232 data cable is shielded and that the shield is properly earthed. Also the cable should not be too long (max 10-15m, but this depends on the application) and should not run near any high voltage lines. 25 to 400 V AC: at least 10cm from the data cable. Anything above 400V AC: 20cm or more from the data cable.  


        



The physical wiring should be done accordingly: 





Step 2 - Creating the MODBUS Template

Now that you a physically connected, the next step is to create the MODBUS register template in Argos. This template is used to tell the Netbiter which parameters will be of interest to the user. In order to create a template you will need to get hold of the MODBUS register table from the slave manufacturer (The Netbiter is a MODBUS Master which queries MODBUS Slaves - in our case, the slave is the ComAp panel).

Tip! You can sometimes save yourself a lot of time by checking to see if someone has already created a template for you. These templates are stored on the Always check this list first: 
Even if you have a different model, you can sometime re-use on of these templates. Sometimes the descriptions are in another language, but even these are re-usable. In January 2014, this was the only template available - we will try re-use it. So download it and save it to a directory on your computer. 


Step 2.1
Log into www.nebtiter.net with your free account. You can only edit/create templates if you logged in as an administrator. Once there, click on "Management" and then on "Templates". Upload the template you have saved. 


Feel free at this point to expand the template tree view and see what groups are available. Remember, your device might not support all the functions of the template. You can within these groups, edit the individual parameters and adjust their Modbus register address, the device name, scaling, etc. Here we have the "run hours" parameter under the group "statistics":

Feel free to create your own parameters or delete ones that you will not use. These will be used later when we create a profile.  




Tuesday, January 7, 2014

PROFIBUS PA Link with Remote Monitoring Capabilities

It's here! Transparent PROFIBUS PA link for 12 Mbps with COMbricks!

PROCENTEC’s transparent PROFIBUS PA link/coupler enables seamless high speed integration to PROFIBUS PA. It powers the attached devices and fully emulates all PA devices as DP devices on the PROFIBUS DP side. It does not require adjusted busparameters and is therefore suitable for all DCS and PLC systems, even ones running on 12 Mbps. The combined internal ProfiTrace and oscilloscope make this product extremely useful for remote maintenance over Ethernet. Jitter, noise, DC current, DC voltage, bar graph and oscilloscope, it is all there and easy to access. The free CommDTM allows access for asset management tools over Ethernet. The PA link is a module that fits in the COMbricks system able to carry 9 PA links and a RS 485 or Fiber Optic module. It can also be a customized mix of PA modules with other communication modules. The PA link can provide 500 mA segment current on a customizable bus voltage.