МBRP-250 starts to operate immediately after connecting
the supply voltage to it. The algorithm of work is as follows:
Starting initialization mode (0.2-0.3 s)
For about 0.2-0.3 s the device is busy with initialization
of important parameters. During initialization the output
is forbidden and the output voltage is 0 V. Leds ‘on’ and
‘prot’ (protection) are active. the output becomes active,
the unit then measures current consumption of the connected
slaves. Led ‘prot’ is turned off, led ‘bus’ (allowed output)
and ‘TX’ (transmit) become active. If short circuit, the
output is held forbidden and after a few second a new check
is done, while led ‘prot’ becomes active, leds ‘bus’ and
‘ТX’ are turned off.
Normal operation mode
Continuously the unit measures current consumption of the
connected slaves. If the consumed current becomes higher
than 450 mA, the led 'over' is turned on. If the consumed
current becomes higher than 470mA, the output is forbidden
and turned off. When connecting to main supply device like
MBRS-xx, MBRP-250 is a dedicated bridge for the connection
between main converter and additional slave devices. The
data is transmitted immediately, without delay. When a slave
device is sending information, this data is first decoded
and then send via m-bus output with no delay. This is indicated
by the blinking of led ‘RX’ (receiving). It is possible
simultaneously to transmit/receive data. If collision (two
or more slave devices send instantly), the led ‘coll’ (collision)
is turned on, although the data is transmitted anyway.