Delta AH500 Manual page 757

At most 1 AH series main backplane, 7 AH series extension backplanes and 68 I/O modules are
connectable to AHRTU-ETHN-5A as shown in the following figure.
When an extension backplane is to be connected, follow the rule of connecting the first port of the
extension backplane to the last backplane and connecting its second port to the next extension
backplane.
Chapter 16 Remote I/O Module AHRTU-ETHN-5A
AHRTU ETHN modules
Main bac kplane 7
RTU -DN ET
Ex tens ion bac kp lan e 1
Ext ension back plane 2
Communicat io n ca ble for ex ten sion ba ck planes
Ps 05 Mod ule
Ex ten sion ba ck plane 7
-
I/O Mo dule
16-7