LEDs
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netTAP NT 50 | Gateway Devices
DOC091202UM09EN | Revision 9 | English | 2013-02 | Released | Public
© Hilscher, 2010-2013
8.4
LEDs Serial Protocols
8.4.1
LED Modbus RTU
The subsequent table describes the meaning of the LEDs for the Modbus
RTU protocol.
LED
Color
State
Meaning
Duo LED red/green
(green)
On
The device has a valid configuration for Modbus RTU and is ready for
Modbus communication respectively sends/receives Modbus RTU
telegrams
(red)
On Communication error:
The device works as
Modbus RTU Master
:
- the slave device answered with a error (Modbus Exception), e. g.
functioncode not supported, access to invalid register addresses or coil
addresses
- receive error detected, e. g. parity error or checksum error - timeout
(slave device does not answer)
The device works as
Modbus RTU Slave
:
- the Modbus RTU Master device uses an invalid functioncode
- the Modbus RTU Master device has accessed an invalid register ad-
dresses or coil addresses
- receive error detected, e. g. parity error or checksum error
- timeout (application does not answer or answers with error)
The error display is set back with the next error free Modbus telegram
sequence
COM
with
protocol at
X2
with
protocol at
X3
(off)
Off
During initialisation or invalid Modbus RTU configuration or missing
power supply
Table 48: LEDs Modbus RTU Protocol
8.4.2 LED
ASCII
The subsequent table describes the meaning of the LEDs for the ASCII
protocol.
LED
Color
State
Meaning
Duo LED red/green
(green)
Flashing cyclic
with 5 Hz
The device sends/receive data
(green)
On
The device is ready for serial communication
(red)
Flashing cyclic
with 5 Hz
The device is configured and is in the state stop
(red)
Flashing cyclic
with 1 Hz
The device is not configured
COM
with
protokocol
at X2
with
protocol at
X3
(off)
Off
During initialisation or missing power supply
Table 49: LEDs ASCII Protocol
