Sterlco A3 Blender Control and Data Acquisition Software - Manual (Page 121)

Page Number 121
Step 4: If all of the previous steps have been satisfied then examine the
“LINK” light on the Ethernet module. It should not be red. If it is then first
make sure that the Ethernet cable is hooked up at both ends. Remember
that you must use straight through standard CAT5 cables when going
between the blender and a hub or switch. If you are trying to go directly
from the blender to a PC without using a hub or switch I’d then you need to
use a Crossed Ethernet cable. At this point you more than likely have a
cable problem and should test this. To test purchase a standard CAT5
cable that already has the ends connected and a standard hub or switch
(this can be purchased from Best Buy, Circuit City, CompUSA, or Radio
Shack). At the blender power up the hub and connect the blender using
the new cable to one of the middle ports on the hub (say port 3 on a 4-port
hub). Examine the LINK light and if it is now clear then the problem is
definitely in your original cabling. This same test can be performed on the
PC and PC cable. All PC Ethernet cards have a LINK light as well.
Establish the LINK light on all devices before proceeding.
Step 6: If you have LINK lights on all units (including the PC) and no fault
link lights on the PLCs, but you still cannot establish communications then
we need to check the PC’s network properties. If this computer resides on
your plant network and was set up by your IT department, then you will
need to involve them for further assistance with your problem. Instruct your
IT department that the blenders must have a fixed IP, but the PC can have
a dynamic IP. All subnet mask for the PC and the blenders needs to be
255.255.255.0. They might not have the startup script correct for your PC.
If the blenders and PC all reside on a separate network that has nothing to
do with your plants LAN then we need to check the PC’s network