Pepper Computer Modular Computers RS485 - Manual (Page 306)

SMART I/O User’s Manual
October 01, 1996 ©1996 PEP Modular Computers GmbH Page 6- 24
Chapter 6 Communications Modules
6.2.7.5 Compare Register
This 24-bit register indicates the comparison value and is cleared after a
power-on reset.
6.2.7.6 Identification Register
The identification register is read only and fixed at a value of $81.
6.2.7.7 Status Register
The 16-bit status register is divided into two sub-registers which are partly
cleared after a power-on reset and show:
• IP : Interrupt Pending flags • DF : Data Flow
• PE : Parity Error • ER1 : End-of-Range 1
• TC : Transmission Complete • ER2 : End-of-Range 2
• OL : Open Line • MH : Match
IP, PE, TC, OL, DF and MH flags are cleared after a reset. ER1 and ER2
represent the current hardware condition
6.2.7.8 STAT1 Register
IP0-PE interrupt pending on parity error
IP1-TC interrupt pending on transmission complete
IP2-ER1 interrupt pending on end-of-range switch 1
IP3-ER2 interrupt pending on end-of-range switch 2
IP4-MH interrupt pending on comparison match
DF SSI data flow (True/False)
OL open line (True/False)
S T 1 - 7 S T 1 - 6 S T 1 - 5 S T 1 - 4 S T 1 - 3 S T 1 - 2 S T 1 - 1
OL unused DF IP4-MH IP3-ER2 IP2-ER1 IP1-TC