Ethernet Configuration - Galil Motion Control DMC-21 5 Series User Manual

Ethernet Configuration

Communication Protocols
The Ethernet is a local area network through which information is transferred in units known as packets.
Communication protocols are necessary to dictate how these packets are sent and received. The DMC-21x5
supports two industry standard protocols, TCP/IP and UDP/IP. The controller will automatically respond in the
format in which it is contacted.
TCP/IP is a "connection" protocol. The master, or client, connects to the slave, or server, through a series of packet
handshakes in order to begin communicating. Each packet sent is acknowledged when received. If no
acknowledgment is received, the information is assumed lost and is resent.
Unlike TCP/IP, UDP/IP does not require a "connection". If information is lost, the controller does not return a colon
or question mark. Because UDP does not provide for lost information, the sender must re-send the packet.
It is recommended that the motion control network containing the controller and any other related devices be
placed on a "closed" network. If this recommendation is followed, UDP/IP communication to the controller may be
utilized instead of a TCP connection. With UDP there is less overhead, resulting in higher throughput. Also, there is
no need to reconnect to the controller with a UDP connection. Because handshaking is built into the Galil
communication protocol through the use of colon or question mark responses to commands sent to the controller,
the TCP handshaking is not required.
NOTE: In order not to lose information in transit, the user must wait for the controller's response before sending
the next packet.
Addressing
There are three levels of addresses that define Ethernet devices. The first is the MAC or hardware address. This is a
unique and permanent 6 byte number. No other device will have the same MAC address. The DMC-21x5 MAC
address is set by the factory and the last two bytes of the address are the serial number of the board. To find the
Ethernet MAC address for a DMC-21x5 unit, use the TH command. A sample is shown here with a unit that has a
serial number of 3:
Sample MAC Ethernet Address: 00-50-4C-58-00-03
The second level of addressing is the IP address. This is a 32-bit (or 4 byte) number that usually looks like this:
192.168.15.1. The IP address is constrained by each local network and must be assigned locally. Assigning an IP
address to the DMC-21x5 controller can be done in a number of ways.
The first method for setting the IP address is using a DHCP server. The
21x5 controller will get an IP address from the DHCP server. If the unit is set to
server on the network, the controller will be dynamically assigned an IP address from the server. Setting the board
to will prevent the controller from being assigned an IP address from the server.
DH0
The second method to assign an IP address is to do so manually through Galil software. When opening the Galil
Software, it will respond with a list of all DMC-21x5's and other controllers on the network that do not currently
have IP addresses. The user must select the board and the software will assign the specified IP address to it. This
address will be burned into the controller (BN) internally to save the IP address to the non-volatile memory.
NOTE: If multiple boards are on the network, use the serial numbers to differentiate them.
Chapter 4 Software Tools and Communication ▫ 26
command controls whether the DMC-
DH
(default) and there is a DHCP
DH1
DMC-21x5 User Manual 1.0a1