You can connect the PC with the Toolbox4 software and the RM4200 Devices either using a serial port or via Ethernet and TCP/IP. If possible, you should use Ethernet, since the transfer speed is higher.

In the Device tree, all Devices are displayed that are connected to the PC with the Toolbox4 software. This includes the Devices that are manually connected via the serial port or by entering the IP address as well as Devices automatically registered by UDP.

The automatic registration works as follows:

Each RM4200D transmits once per second a UDP broadcast message over Ethernet that contains the following data:

As soon as these UDP messages reach the Toolbox4 PC, it processes the data and displays the information in the Device tree. In addition, you can manually add further Devices that can not be registered automatically by UDP. Use the command Add Device… from the menu Device.

	Important
	If the Toolbox4 PC is connected to a network segment different from the one of the RM4200D Devices, it can happen that the UDP broadcast messages can not be transferred over the border of the segment. In this case, automatic registration does not work!

To solve this problem, the transport of UDP messages must be enabled by the network administrator. In most cases, this is carried out for certain Ethernet MAC addresses.

DHD has reserved the MAC address range 00:0A:63:xx:xx:xx for its products. The last three bytes xx:xx:xx of the MAC address are consecutively assigned by DHD to each Communication&Logic Controller RM420-850 during production. Each RM4200D must contain one of these controllers. The MAC address assigned during production can not be changed later on! Therefore, apart from the unique identification for data transfer in the network, it is used for assigning the license codes of RM4200D. (see also Enter license code)

	Warning
	The MAC address of a RM4200D is permanently assigned to the hardware of the Communication&Logic Controller RM420-850 and can not be changed! Thus, when replacing the module RM420-850, also the MAC address of the RM4200D changes. In this case, you also must order new license codes!

Important

The Toolbox4 software was developed for Windows XP, but runs on other Windows versions as well. A known bug in certain versions of Windows NT prevents the reception of UDP broadcast messages. This is the reason why automatic registration does not work, even if the Toolbox4 PC and the RM4200D are located in the same network segment. In this case you must access the Devices manually via their IP addresses using the command Add Device…. (see also Add device... (Setting up a connection to RM4200D manually))

Please find more detail on the protocols UDP and TCP/IP in the standard literature on computer networks or ask your network administrator.

Connections using Wide Area Networks

The RM4200D uses the TCP/IP protocol for the communication between DSP frames and the Toolbox4-PC. In theory, you could remote control RM4200D systems over Wide Area Network links (WAN), which carry TCP/IP traffic. However, in practice this does not always work properly, because of the following:

• On WAN links, data throughput and latency are often not predictable and can change suddenly. This applies especially, if the connection is made using the “open Internet” instead of a dedicated data line.

  In contrast to a standard PC a RM4200D is a embedded system that also happens to use TCP/IP. However, concerning TCP/IP transmission, it is not as robust and fault tolerant as the PC. This is no problem in local networks, where communication is reliable. However, if the data has to travel over a WAN link, data can get lost under certain circumstances. This loss of data can sometimes have unwanted results.

Therefore you should not try to remote control RM4200D systems over WAN links!

	Warning
	Especially, do not try to update the firmware of the RM4200D over a WAN link!

If you really need to remote control a RM4200D use a remote control software like Norton PC Anywhere, Timbuktu Pro or VNC. Use this software to remote control a PC, which is in the same local network as the remote RM4200D.

If you do need to use WAN links, pay attention to the following facts:

• The less additional traffic is on the line the more stable the data connection will be.

  If you have the choice, you should rather use a dedicated data line than the Internet.

  Sometimes it helps to dial up the remote PC directly over ISDN instead of using a WAN link.

  Make sure you mind the usual rules for tunnelling private data traffic over public networks (VPN, access restrictions etc.) Ask your system administrator about it.