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PD 664 System configuration and requirements
SIM card requirements
The majority of service provider’s supports GPRS communication on “Contract” or “Pay as you go” (PAYG).but some service providers don’t support GPRS on a PAYG basis. If there is any doubt, contact should be made with the service provider of the SIM card.
If a Pin Code is associated with the SIM card it is essential to have this information available during the configuration of the PD 664 GPRS Interface.
Access Point Name SettingsIn order to configure the PD 664 GPRS Interface, is it necessary to obtain information about the APN settings. This information is often available on the service provider’s homepage or can be obtained by contacting the service provider.
The settings to use vary according to which network is to be used, and can sometimes be different if it is a contract or PAYG account.
Connecting to the P-NET Gateway ServiceIf the PD 664 GPRS is not able to connect to the Gateway Service, the variable GPRS.LastError can be very useful, and consists of an ID number and a error text string. If the problem is related to the network or incorrect APN settings, the register shows ID number 616 – “Network is down”. The Link LED in the PD 664 indicates whether the GPRS interface is connected or not. OFF indicates no GPRS connection.
Installation of the P-NET Gateway Service
The P-NET Gateway Service is included in the VIGO 5.8 The Fieldbus Management System suite, and can be installed on PCs running Windows XP Professional, Windows Vista, Windows server 2003 or Windows server 2008. The P-NET Gateway Service is also available as a separate installation suite and it can run independently of VIGO.
The P-NET Gateway Service acts and is visually structured using modules having channels and ports, just like other P-NET devices. But unlike physical hardware modules, the Gateway Service is a group of Virtual Modules because it is actually just configurable software running on a PC.
The PC used for the P-NET Gateway Service can , for example, be a standard PC, a laptop or a small low power DIN rail mounted industrial PC without locally connected monitor, keyboard etc.
Standard system installationServerPROCES-DATA recommends that the P-NET Gateway Service is installed and runs on a separate PC (server). The server can be physically located anywhere in the world, as long as it has an Internet connection. Any PC with VIGO installed and an Internet connection will be able to communicate with the P-NET Gateway Service, and all the mobile / remote stations that are connected to the Gateway Service.
The Server can either be connected directly to the Internet, having a public IP address related to the server, or it may be located behind a router where the router is configured to use port forwarding to forward communication received on port 34380 (default port), through to the server on a local sub-net. The public IP address is, in this instance, usually the IP address assigned to the router itself. Because the server may not be protected by a sufficiently secure firewall as standard, PROCES-DATA recommends that UDPSec or similar such security protection is used.
ClientsWhilst TCP packet data between the Gateway Service and a PD 664 GPRS module is already encrypted, P-NET UDP data between a monitoring PC and the Gateway Service is not in a standard (port 34380) configuration. This may not be particularly important if the monitoring PC is on the same local network as the Gateway PC or server and behind a firewall. However, to ensure that such data can be made secure for any client-server situation, two utility programs are available. These are the ‘Key Manager’ and the ‘Key Generator’ and are found in the ‘PROCES-DATA’ program folder, under ‘P-NET Gateway Service’. The method of encryption using the UDP communication through port 34381 is achieved by means of a generated ‘key’. The user of the client or monitoring PC will be informed as to what the global IP address of the Gateway service is, a user name and a password, all of which is, initially at least, declared using the Key Manager in the Gateway PC.
Simple system installationServerThe PC (server) running the P-NET Gateway Service can be located behind a firewall/router as shown in the system examples. If a firewall is present, it will be required that default port 34380 is opened for TCP communication. A port forward rule needs to be enabled for this port in order to forward all communication for this port to the server. Configuration of port forwarding is usually detailed in the technical manual of the router hardware, and often available for download from the manufacturers web site.
ClientsA simple system installation will allow any PC connected to the same network to communicate with a Gateway Service and all mobile / remote stations connected to it. It is therefore not advisable to allow PCs to connect to the Gateway Service though port 34380 (UDP) without any form of authentication, because of the possible security risk.
VIGOIn VIGO 5.8, a GPRS Workspace is provided together with a project called GPRS This project can be used, amended or expanded to match a planned real project, or used as a example of what is required to expand a currently operational project. Link to Description of the provided workspace.
The IP address for the UDP port within the Gateway Service is set to 127.0.0.1:34380 as default (the standard internal address of the local machine or ‘host’). It should be ensured that before use, the IP address for the UDP port within the P-NET Gatway(service) node, is changed if necessary to point to the actual IP address or URL that will directly or indirectly connect (through a router) to the PC acting as the server.
If the Gateway Service is running on the same PC as the one running VIGO and this is used for communication, the UDP port for the node P-NET Gateway(Service) can remain as 127.0.0.1:34380 (localhost). 127.0.0.1 is the standard IP address used for a loopback network connection. This means that if you try to connect to 127.0.0.1, you are immediately looped back to your own machine.
If the Gateway Service is running on another PC on the same network, the IP address for the UDP port must be set that PCs IP address.
Configuration of the P-NET Gateway Service
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