6
Host interface,
ANSI X3.28
protocol
The ANSI X3.28 protocol is described, for ex-
ample, in "Allen-Bradley: 1771-811 PLC-2-
family/RS 232C Interface module 1771-KG;
Users’s Manual". With this protocol the SRIO
500M can communicate with, for example
ABB’s Substation Control System SCS 100,
ABB’s Remote Control System S.P.I.D.E.R
MicroSCADA and Allen-Bradley’s PLC 2.
The protocol used by the SRIO 500M unit is
the same as that of Allen-Bradley, except that
the ways of presenting data have been extended.
Analog data base data is transferred in 32 bit
integer format or in BCD format. Digital data
base data is transferred in 16 bit binary format.
EV-data from the data base is transferred using
16 bits for data and 32 bits for time stamps.
Parameter data is transferred in ASCII format.
The clock time is transferred in BCD format.
Events with time markings are sent to the host
using 32 bits transmitted for event identifica-
tion and 32 bits for time stamps.
Data base data, i.e. process data, is transferred
to the host either on request or spontaneously
when there is a change in the data. Parameter
data is transferred only on request. Events are
transmitted spontaneously.
Host interface,
SACO 100M
protocol
The SACO 100M protocol used for the SRIO
500M host interface is described in document:
"SACO 100M communication protocol for
data communicators SRIO 500M and SRIO
1000M".
Programming
The SRIO 500 M unit is programmed from a
display terminal or a PC provided with a termi-
nal emulator program. The display terminal can
be connected to the SRIO 500M unit, serial
interface 4. By turning the front panel switch 1
to ON position the communication parameters
of the serial interface 4 are set at: 1200 b/s, 8
data bits, no parity, 1 stop bit.
The programming language is a command lan-
guage based on ASCII characters. The program-
ming is described in detail in the "PROGRAM-
MING MANUAL SRIO 1000M AND SRIO
500M".
Figure 3. Connection to programming terminal.
Display
SRIO
PC/AT
SRIO
terminal
500M
serial port
500M
25- pin male
25- pin male
9- pin female
25- pin male
D-connector
D-connector
D-connector
D-connector
RXD 3 ———2 TXD
RXD 2 ——— 2 TXD
TXD 2 ———3 RXD
TXD 3 ——— 3 RXD
GND7 ———7 GND
GND5 ——— 7 GND
Cable between a display
Cable between 9-pin serial port
terminal and SRIO 500M.
of a PC/AT and SRIO 500M.
Figure 4. Cables for connecting a terminal or PC to the SRIO 500M unit.
SRIO 500M
RS 232 C
2
4
1
Display terminal or
PC with terminal
emulator program
