Rockwell Automation 1785-KA5P/B DHP COMM. ADAPATER MOD. - Manual (Page 45)

Communicating through the 1785ĆKA5
Communication Adapter Module
Chapter 3
3-17
The data transfer rate is much higher for DH+ links (57.6 KB) than for
DH485 links (19.2 KB), so DH+ devices must control the flow of data to
DH485 devices. For example, a DH+ device can send packets to the
1785-KA5 adapter three times faster than the gateway can send the packets
out to their DH485 destinations.
The 1785-KA5 adapter module provides only a limited amount of buffer
space to account for short term bursts of data transfer. The DH+ device
must meter out or otherwise provide other means for flow control to
prevent buffer overflow in the gateway.
Controlling the Flow of Data