HEIDENHAIN SHB Data Interfaces for HEIDENHAIN - Manual (Page 9)

2 – 10 HEIDENHAIN Service Manual for Data Interfaces
2.2.2 Signal levels
With the V.11/RS-422 interface the signals are both transmitted and received as differential
voltage.
A positive differential voltage means a logical zero (OFF), a negative differential voltage means
a logical one (ON).
Differential voltages between
U
dmin
= 2 V and U
dmax
= 5 V are output; the control detects the differential voltages
between
U
dmin
= 0.2 V and U
dmax
= 6 V as logically defined levels.
2.2.3 HEIDENHAIN data transfer software
See chapter 2.1.3
2.3 Ethernet
Ethernet technology is most frequently used in local networks. It was developed by Digital
Equipment, Intel and Xerox in 1982. Ethernet operates at a data transfer rate of up to 100 Mbps
(Fast Ethernet); the hardware versions most frequently used - such as 10Base2 (Thin Ethernet,
Cheapernet), 10Base5 (Thick Ethernet, Yellow Cable) or 10BaseT (Twisted Pair) - operate at
10 Mbps. They differ in price, routing complexity or network topology, but not in the method of
accessing media.
The data transfer rate strongly depends on the amount of traffic at the time on the net.
Realistic values: NC program up to 200 Kbps
ASCII file up to 1 Mbps