Com 0 And Com 1; Note For Termination Resistors For Com 0 In Rs-485 Mode; Note For Termination Resistors For Com 1 In Rs-485 Mode; Note For Fail-Safe Resistors For Com 0 In Rs-485 Mode - Eurotech ReliaGATE 10-12-6 Series User Manual

9 Interfaces in detail
9.5

COM 0 and COM 1

The ReliaGATE 10-12 provides the following COM ports:
1x RS-422/485: COM 0; Surge protected, Insulated, Full Duplex/Half Duplex
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(Default: RS-485 Full Duplex)
1x RS-232/485: COM 1; Surge protected, RS-485 termination and fail-safe resistors
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(Default: RS-232)
COM ports specifications:
The COM ports are surge protected
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Both COM ports are disabled when the ReliaGATE 10-12 is initially powered ON
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Maximum supported baud rates are:
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The COM connectors are available on the front side.
For more information
9.5.1

Note for termination resistors for COM 0 in RS-485 mode

The termination resistors can be driven using the "gpio_utility".
For more information see:
9.5.2

Note for termination resistors for COM 1 in RS-485 mode

COM 1 has 2 pairs of pins (each signal is doubled):
If the ReliaGATE 10-12 is located at the beginning, or at the end, of a RS-485 chain, spare pair of
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pins can be used to connect permanently standard axial resistor 120 Ohm, if the application
requires that
If the ReliaGATE 10-12 is not at the beginning or at end of the RS-485 chain, two options are
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available:
9.5.3

Note for fail-safe resistors for COM 0 in RS-485 mode

Fail-safe resistors (1.21 kΩ) are already inserted by default and cannot be removed by the user.
56 / 118
For RS-232 mode: up to 450 kbps
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For RS-485 mode: up to 1.75 Mbps
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see:"How to manage the COM ports" on
"How to drive the GPIOs: the GPIO Utility" on
Option 1: one pair of pins can remain not connected
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Option 2: one pair of pins can be used to connect the previous device of the chain,
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and the other pair can be used to connect the following device of the chain
ReliaGATE 10-12 User manual Rev. 2-1
page 77.
page 71.