INVENTIA MT-101, Руководство пользователя

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Bear in mind that:
•
In communication with Slave devices, the module employs standard MODBUS RTU
frames, with functions 1, 2, 3, 4 for reading, functions 5, 6 do for writing singular
changes and functions 15 and 16 for block writing.
•
Upon power up or start of communication with peripheral equipment, the module
synchronizes Mirrored space with with Slave's contents, updating its registers with
Slave contents. This assures that writing values to Mirrored space during interrupted
communication with the slave will not overwrite slave's values upon reestablishment
of communication. Bits informing about state of communication with slaves (SL1_ok ..
SL16_ok)corresponding to defined during configuration areas, reside in transmission
in binary inputs space. High corresponding bit signals good communication with
particular slave.
•
In Modbus RTU Mirror mode Slaves mirrored in module can not transmit events.
When servicing events from slaves is required, standard Modbus RTU Slave mode is
recommended.
7.7. Transparent PLUS mode
Transparent PLUS mode is an extension of standard Transparent mode enabling access to
internal resources of the module using standard Modbus frames. The Module inspects every
frame received via GPRS analyzing syntax and CRC. Upon detection of Modbus RTU frame
addressed to the module (matching ID), the frame is not sent to PORT2. The module
carries out the instruction and sends confirmation to the sender only, regardless of number
of addresses defined in GPRS section.
The function of channel reservation is independent of access frames. Reception of access
frame does not reserve the channel. Access to the module from another master during
channel reservation is possible.
Bear in mind that:
•
In this mode the module may exchange GPRS data correctly with modules operating
in Modbus Master mode, Modbus Slave, Modbus Mirror if the CRC option is set to Yes
in Modbus modes.
•
During analysis of received frames, the highest priority is assigned to access frames
(frames with the structure compliant with Modbus frame). Such frames will not be
sent to serial port.
•
The access to internal resources from serial port is not possible.
7.8. GazModem mode
GazModem mode is an extension of Modbus RTU Slave mode with functionality similar to
that available in Modbus Mirror mode with mapping of register space of peripheral Slave
into MT-101 internal registers.
This mode was implemented due to requirement of reading from devices operating in Gaz-
Modem and Gaz-Modem2 protocols created by Plum Sp. z o.o. for use in different
volumetric gas counters and other gas systems. The user employing telemetry modules is
capable of reading current data, binary inputs and alarm signals from gas devices.
7.9. M-Bus LEC mode
M-Bus LEC mode is an extension of Modbus RTU Slave mode with functionality similar to
that available in Modbus Mirror mode with mapping of register space of periferal Slave into
MT-101 internal registers.
This mode was implemented due to requirement of reading from devices operating in M-
Bus protocol, applied mainly for measuring of energy consumption in heating systems.