Allen-Bradley devicenet modules in logix5000 control systems Manual De Usuario
Publication DNET-UM004A-EN-P - March 2004
Automatically Configure a DeviceNet Network 4-13
Consideration:
Description:
1. The bytes/node value defines how
much memory for each address.
AutoScan lets you specify how much input and output memory to give to each address on
your network.
your network.
2. The scanner sets-up communication
with any device that fits within the
allocated memory size.
allocated memory size.
The scanner automatically sets up communication with those devices that fit within the
memory allocated for each address.
memory allocated for each address.
• For example, if you allocate 2 DINTs (8 bytes) per address, the scanner sets up
communication with any device that sends or receives 1 - 8 bytes of data.
• The scanner adds as many device as it can until it runs out of memory.
• If you give too much memory to each address, you may not have enough memory for
• If you give too much memory to each address, you may not have enough memory for
all your devices.
3. The scanner skips devices that are
too large.
If a device needs more memory than is allocated, the scanner skips it and does not set up
communication with it.
communication with it.
For example, if you specify 2 DINTs (8 bytes) per address but a device sends 9 bytes, the
scanner does not add the device to the scan list.
scanner does not add the device to the scan list.
4. Manually editing the scan list turns
off AutoScan.
If you use RSNetWorx software to edit the configuration of the scanner, the scanner turns
off AutoScan. Do not turn it back on or you will clear the configuration that you just
entered.
off AutoScan. Do not turn it back on or you will clear the configuration that you just
entered.
For example, if you use RSNetWorx software to manually add a device to the scan list, the
scanner turns off AutoScan. If turn on AutoScan again, the scanner clears it current
configuration and starts over.
scanner turns off AutoScan. If turn on AutoScan again, the scanner clears it current
configuration and starts over.
DINT
Input Memory
0
device at address 0
1
2
device at address 1
3
4
device at address 2
5
The actual data for the device fills the portion
that it needs and the rest remains unused.
For example, if you specify 2 DINTs (8 bytes)
per address, the scanner sets aside 2 DINTs
for each address.