Schweitzer Engineering Laboratories SEL-734 - MIRRORED BITS Protocol for Pulsar 9600 Baud Modem; Settings

G.4
SEL-734 Meter Instruction Manual Date Code 20090730
MIRRORED BITS Communications
M
IRRORED BITS Protocol for Pulsar 9600 Baud Modem
MIRRORED BITS Protocol for Pulsar 9600 Baud Modem
You can indicate that a Pulsar MBT modem is to be used by responding with
an entry of MBT to the RTS/CTS setting prompt. When you select MBT, the
baud rate setting will be limited to 9600 baud.
NOTE: The MBT mode will not work
with PROTO = MB8A or MB8B.
The MIRRORED BITS protocol compatible with the Pulsar MBT9600 modem is
identical to the standard M
IRRORED BITS protocol, with the following
exceptions:
➤ The meter injects a delay (idle time) between messages. The
length of the delay is one meter processing interval.
NOTE: An idle processing interval
guarantees at least 19 idle bits at
9600 baud in an SEL-734 Meter with
the system frequency at 65 Hz.
➤ The meter resets RTS (to a negative voltage at the EIA-232
connector) for M
IRRORED BITS communications through use of
this specification. The meter sets RTS (to a positive voltage at
the EIA-232 connector) for M
IRRORED BITS communications,
using the R6 or original R version of M
IRRORED BITS.
Settings
Protocol(SEL,LMD,DNP,DNPE,MBA,MBB,MB8A,MB8B) PROTO = MB8A ?
Set PROTO = MBA or MB8A to enable the MIRRORED BITS protocol
channel A on this port. Set PROTO = MBB or MB8B to enable the M
IRRORED
B
ITS protocol channel B on this port. The standard MIRRORED BITS protocols
MBA and MBB use a 7-data bit format for data encoding. The MB8 protocols
MB8A and MB8B use an 8-data bit format, which allows M
IRRORED BITS to
operate on communication channels requiring an 8-data bit format. For the
remainder of this section, PROTO = MBA is assumed.
Baud Rate(300-38400) SPEED = 9600 ?
Use the SPEED setting to control the rate at which the MIRRORED BITS
messages are transmitted, in power system cycles (~), based on Table G.1:
Enable Hardware Handshaking(Y,N,MBT) RTSCTS= N ?
Use the MBT option if you are using a Pulsar MBT9600 baud modem. With
this option set, the meter will transmit a message every 1/2 power system
cycle and the meter will deassert the RTS signal on the EIA-232 connector.
Also, the meter will monitor the CTS signal on the EIA-232 connector, which
Table G.1 Using the SPEED Setting to Control MIRRORED BIT Rates
SPEED SEL-321 SEL-734
38400 1 message per 1/8 cycle 1 message per 4 ms
19200 1 message per 1/8 cycle 1 message per 4 ms
9600 1 message per 1/4 cycle 1 message per 4 ms
4800 1 message per 1/2 cycle 1 message per 8 ms
Courtesy of NationalSwitchgear.com