Communications: Appendix – B
B–1
The M-3520 Intertie Protection Relay incorporates
three serial ports for intelligent, digital
communication with external devices. Equipment
such as RTUs, data concentrators, modem, or
computers can be interfaced for direct, on-line real
time data acquisition and control.
Generally, all data available to the operator through
the front panel of the relay, with the optional M-3931
HMI module is accessible remotely through the
BECO 2200 data exchange protocol. This protocol
document and the BECO 2200 M-3520 database-
specified protocol document are available from the
factory or our website at www.beckwithelectric.com.
The M-3822 IPScom
®
Communication Software
package has been supplied for communication to
any IBM compatible computer running under
Microsoft
®
Windows 95 or higher.
The protocol implements serial, byte oriented,
asynchronous communication, and can be used to
fulfill the following communications functions:
•
Real time monitoring of line status.
•
Interrogation and modification of setpoints.
•
Downloading of recorded oscillograph
data.
•
Reconfiguration of functions.
■
■
■
■
■
NOTE:
The following restrictions apply for
MODBUS protocol use:
1.
MODBUS protocol is not supported on
COM1
2.
Parity is supported on COM2 and COM3
only, valid selections are 8,N,2; 8,O,1;
8,E,1; 8,N,1; 8,O,2; 8,E,2 . ASCII mode
is not supported (RTU only)
3.
Standard baud rates from 300 to 9600
are supported
4.
Only the following MODBUS commands
are supported:
a. Read holding register (function 03)
b. read input register (function 04)
B
Appendix B – Communications
c. Force single coil (function 05)
d. Preset single register (function 06)
6.
MODBUS does not support oscillograph
record downloading.
For detailed information on communications, refer
to Chapter 4,
IPScom Computer Operation.
Communication Ports
The M-3520 has both front and rear panel RS-232
ports, and a rear RS-485 port. The front and rear
panel RS-232 ports are 9-pin (DB9S) connector
configured as DTE (Data Terminal Equipment) per
the RS-232C standard. Signals are defined in Table
B-1.
The RS-485 port is assigned to the rear panel
terminal block pins 1 through 4 (see Figure B-2).
This can be configured for isolated RS-485 two-wire
or non-isolated four-wire operation.
■
■
■
■
■
NOTE
: Four-wire operation is only available as a
non-isolated RS-485 supplied option.
Each communication port may be configured to
operate at any of the standard baud rates (1200,
2400, 4800, and 9600). The RS-485 port shares
the same baud rate with COM2 (or COM1 – see
Section 5.3).
While the RS-232 communication ports do include
some Electrostatic Discharge (ESD) protection
circuitry, they are excluded from passing ANSI/
IEEE C37.90.1-1998. Beckwith Electric
recommends the use of RS-232 to fiber optic
converters to avoid any question of surge-withstand
capability.
A null modem cable (see Figure B-1) allows di-
rect connection to a personal computer (PC), if
desired.
Summary of Contents for M-3520
Page 1: ...Instruction Book M 3520 Intertie Protection Relay ...
Page 83: ...2 50 M 3520 Instruction Book This Page Left Intentionally Blank ...
Page 95: ...M 3520 Instruction Book 3 12 This Page Intentionally Left Blank ...
Page 133: ...M 3520 Instruction Book 5 12 This Page Intentionally Left Blank ...
Page 195: ...A 20 M 3520 Instruction Book This Page Intentionally Left Blank ...
Page 213: ...D 12 M 3520 Instruction Book This Page Intentionally Left Blank ...