Ethernet Communication Module DVPEN01-SL
DVP-PLC Application Manual
24
1. Enable IP Filter Function:
Check the box to enable IP filter.
2. IP:
IP addresses that are allowed to establish connections. Maximum 8 IPs are allowed.
3. Netmask:
The subnet of the IP is allowed to establish a connection. To see whether the destination IP is
allowed, conduct bitwise AND operations between the allowed IP and subnet mask and
destination IP and subnet mask. If the two values obtained are the same, the destination IP is
allowed by the IP filter. For example, assume the IP is 192.168.0.1 and subnet mask
255.255.255.255, the only one IP allowed to establish a connection is 192.168.0.1. If the subnet
mask is 255.255.255.0, the IPs allowed to establish connections will become 192.168.0.0 ~
192.168.0.255.
5.7 Static
ARP
Table
ARP (Address Resolution Protocol) is used for obtaining the MAC address corresponding to the IP address
in data transmission. For example, there is a datum to be sent to 172.16.155.250, but you do not know the
corresponding MAC address. You can use ARP to look up the MAC address by IP address, and the
corresponding MAC address will be saved, so you do not need to look it up again when sending the next datum.
Therefore, if you do not know the MAC address, you will have to spend some time looking up the MAC address.
If you want to enhance the transmission efficiency, use static ARP table to save time. For example, assume IP:
192.168.0.1 and MAC: 00:14:22:56:0F:7F. As long as there are data sent to 192.168.0.1, you will get the MAC
address from the table.
Setting up static ARP table
