Siemens IM151-8 - Networking

Ok then guys,

I have a IM151-8 controlling a small stand alone filling/packaging line. When it was delivered it was set with the default 192.168.0.x IP addresses for the equipment. I now want to get the system onto the rest of my site network so i can show on SCADA, log data, etc....

I think i will have to change the IP address of the drives, remote IO modules, the HMI and the PLC. A bit of a change but i was wondering if it was possible to leave the IP addresses of the equipment the same, plug in the new network cable to the IM151-8 and allow the built in switch to handle the traffic or configure a port on the unit to be a different IP?

Any thoughts / ideas on this?

Ash

If the HMI/SCADA is on the "machine network" then what is typically done is to setup a system of fixed IP addresses within the same subnet.

If the HMI/SCADA is on the "office network" or other network governed by someone else (IT department ... ), then what is typically done is to have a router connect the machine network or networks to the higher level network.
Each machine network is setup a system of fixed IP addresses within the same subnet, and with the Router IP as the "Router" or "Gateway" in each device. The Router must then have a fixed IP on the machine side, and something else on the higher level side (can be DHCP, or fixed IPs governed by the IT department).

The switch in the IM151-8 is an unmanaged switch. So it cannot do routing between diverse subnets. And they 3 ports all have the same IP. You cannot configure different IPs.
If all the equipment is within the same subnet, you dont need anything else than to connect everything together.
If not, then there must be a Router somewhere else.

Cheers Jesper,

IM151-8 Network: 192.168.0.x

Siemens Network On Site: 10.4.147.x

Bradley/Main Scada Network On Site: 172.16.1.x

I have a router connecting the two existing networks, siemens & AB. My plan was to migrate the IM151-8 plc to one of the networks.

Thought id ask first to see if i could have got around it by assigning the PLC an address and keeping the drives/io addresses the same. Didnt know how intelligent the inbuilt switch was.

Ash

I really recommend as the very minimum change the IP 192.168.0.x to something else.
Many Routers have a standard IP within 192.168.0.x, which will cause problems with routing to a network that is also in this range.

The independent network is not connected to anything else...yet. I plan to but that is why I am looking at migrating all of the ip addresses first.

Currently in the AB network, I have the PLCs connected to the 172.16.1.x range, then an additional Ethernet card set up for all of my remote io modules with an up range of 192.168.0.x yes it's a default range but only equipment we put in goes into this small local network.

I was hoping I may have been able to do similar with the 151

Thanks for your advice on this ����

AshleyParr said:

The independent network is not connected to anything else...yet. I plan to but that is why I am looking at migrating all of the ip addresses first.

Currently in the AB network, I have the PLCs connected to the 172.16.1.x range, then an additional Ethernet card set up for all of my remote io modules with an up range of 192.168.0.x yes it's a default range but only equipment we put in goes into this small local network.

I was hoping I may have been able to do similar with the 151

Thanks for your advice on this ����

Click to expand...

The IM151-8 can only have one IP address. Larger Siemens PLCs can have communication cards to add extra interfaces, but the IM151-8 doesn't have any Ethernet expand-ability.

As Jesper said, however, you can define a router/gateway for the device, which would allow it to send packets to devices outside its own network, as long as there is actually a real router that exists to bridge these different subnets. PN traffic cannot be routed (PLC to IO), but your SCADA system should be able to grab data out of the IM151-8, even though it is a different subnet, as long as the routing is set up correctly.

That said, moving it onto the larger network would probably simplify things.