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I.L. 66A7508H05
Effective September 2003
RS485 Network-A is the non-inverting differential connection
for the Modbus RTU network. RS485 Network-B is the
inverting differential connection for the Modbus RTU network.
Figure 4: Indicators
5.0 SWITCHES AND INDICATOR LEDS
Refer to
Figure 4
to locate the status LED for the mMINT
module.
Figure 5
shows the location of the configuration
switches.
5.1 Modbus RS485 Network Rx LED [Green]
The LED will be lighted whenever the module is receiving from
the Modbus RTU network.
5.2 Modbus RS485 Network Tx LED [Green]
The LED will be lighted whenever the module is transmitting on
the Modbus RTU network.
5.3 INCOM Network Rx LED [Green]
The LED will be lighted whenever the module is receiving from
the INCOM network.
5.4 INCOM Network Tx LED [Green]
The LED will be lighted whenever the module is transmitting on
the INCOM network.
5.5 Status LED [Green]
This indicator will be flashing whenever the module is powered
up and the microcontroller is executing instructions. The
flashing rate is approximately 1 second ON / 1 second OFF.
However, detection of a communications error on either the
Modbus or INCOM network will result in an increased flashing
rate approximately ½ second ON / ½ second OFF. The rate
will return to normal when the network's diagnostic reset
subfunction (clear UART or slave counters, respectively) is
processed by the mMINT. See Section 6.9 and
Table 6
.
Figure 5: Switches
5.6 INCOM
100
Ω
Termination Dip Switch (SW1)
This switch should be moved to the “ON” position only when it
is the last unit in a chain of units or if it is a single unit.
5.7 Modbus RS485 Baud Rate Dip Switch (SW2)
To configure the data transfer rate for the Modbus RTU
network, three switches in dip switch SW2 should be moved to
either the “CLOSE” or the “OPEN” position based on the rate
required. Refer to
Table 4
. SW2-1 is for mMINT diagnostics.
Baud
SW2-1
SW2-2
SW2-3
1200
X
CLOSE
CLOSE
9600
X
OPEN
CLOSE
19200
X
CLOSE
OPEN
Table 4: RS485 Baud Rate Switches (Normal)
5.8 Unique mMINT Address (SW2)
The mMINT can be assigned address 247 and 248. For the
mMINT to respond to a diagnostic query related to address
247 or 248 on the Modbus network, move dip switch SW2-1 to
the “OPEN” position. Refer to
Table 5
. Normally, this switch is
in the “CLOSE” position.
