1.3 Definitions and abbreviations
CRC
Cyclic Redundancy Check. A
data error detection method.
Device
A node on the Modbus RTU
network.
Grundfos GO Remote
Grundfos GO Remote is an app
for setting up, controlling and
monitoring Grundfos products.
The app can be downloaded for
free in your preferred app store
for both Android and iOS.
MAC
Unique network address for a
piece of hardware.
Transmission speed
Bits transferred per second,
bits/s.
Parity
An error checking
method. When a message is
transmitted, the parity bit is
calculated and applied to the
data frame of each character
transmitted (every 7 bits in
ASCII Mode, or every 8 bits in
RTU Mode). The receiving
device counts the quantity of 1
bits in the data portion of the
frame and sets an error flag if
the count differs from that
received.
Line termination resistors (only
Modbus RTU)
Line termination must be
connected at each of the two
ends of the segment medium.
The MIXIT unit is fitted with a
built-in optional line termination
resistor.
Upgrade packages
MIXIT can be upgraded with
DYNAMIC and CONNECT.
DYNAMIC:
The DYNAMIC upgrade
offers balancing limiters
functions and pressure
independence. It also gives
access to the Grundfos
BuildingConnect Free
Monitoring solution.
CONNECT:
CONNECT is suitable when
MIXIT operates as a subsystem
in large installations where a
BMS system is already in place.
The upgrade enables you to
connect MIXIT to a building
management system via
fieldbus (BACnet or Modbus)
and gives access to Grundfos
BuildingConnect Professional.
The DYNAMIC and CONNECT
upgrades can be combined.
1.4 BACnet bus topology
BACnet MS/TP is a multi-master system, meaning that there can be
more than one master on the network. It uses a token to control
access to the bus network. A master node may initiate the
transmission of a data telegram when it holds the token. Both
master and slave nodes may transmit data telegrams in response to
requests from master nodes, but slaves never hold the token.
Master nodes pass the token between them. A BACnet MS/TP
segment is a single contiguous medium to which BACnet nodes are
attached. Segments can be connected by use of repeaters or
bridges, thus forming networks. Multiple networks may be
interconnected by BACnet routers to form a BACnet inter-network.
M
S
S
S
M
M
BR
LT
S
LT
TM044274
Pos.
Description
M
Master
S
Slave
BR
Bias resistor
LT
Line termination
1.4.1 Line termination resistors
Line termination must be connected at each of the two ends of the
segment medium. The MIXIT unit is fitted with built-in optional line
termination resistor.
Related information
1.4.2 Bias resistors
The BACnet system integrator must specify if and where a bias
resistor is needed. A bias resistor ensures that an undriven
communications line will be held in a guaranteed logical one
state. The bias provides a reliable way for stations to detect the
presence or absence of signals on the line. An unbiased line will
take an indeterminate state in the absence of any driving node. The
MIXIT unit has no bias resistors.
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English (GB)
