Black Box IC108A Guia do Utilizador descarregar pdf (Página 35)

Advant

Smart Device (HART

) Interface User’s Guide

Section 2.3.1 Connecting to a SHIM

3BUR 001 085R0001 REV A 2-23

devices multiplied by 5,000 pF. For smart devices without CN values, use 1.

Masters (primary and secondary) need not be counted in deriving C

2.3.1.6 Digital Signals Only

Digital signals of smart devices are brought into a Advant Controller via SHIMs connected to

the MVI serial ports.

For digital communication only with smart transmitters, a SHIM can supply loop power to

smart transmitter loops and provide digital communication to MVI port using RS-232 directly

or for multiple SHIMs using the RS-485 bus through a RS-232/485 converter.

Since analog input termination panels are not used for digital only communication with smart

devices connected to a SHIM, a 250 ohm 1% 5W resistor is required. This resistor is needed to

provide the 250 ohm HART loop resistance that converts the HART FSK current to a voltage

(1V to 5V) that the SHIM can read.

NOTE

In the field, you can tune a smart device communicating only digital signals to the

Advant Controller by attaching a hand-held monitor to its smart transmitter loop

using grapper hooks across its terminals or the resistor attached between its

corresponding SHIM Signal+ and Signal- connections. Any tuning changes you

make to the smart device with the hand-held monitor are not logged by the

Advant OCS.

2.3.1.7 Analog and Digital Signals

Advant Controllers can support both analog and digital communication with smart devices or

just digital communication as described above. The analog signal from a smart device is brought

into the Advant Controller using either S100 I/O, S800 I/O or Taylor Remote I/O (TRIO). The

digital signal from up to eight smart devices is AC coupled to the SHIM.

S100 I/O

Analog signals brought into an Advant Controller employing S100 I/O use either DSAI 130

Analog Input boards, DSAI 133 Analog Input boards or DSAX 110 Analog Input/Output

Boards. The DSAI 130 has terminations for 16 analog inputs, the DSAI 133 has terminations

for 32 analog inputs and the DSAX 110 has terminations for 8 analog inputs.

In the AC 410 the S100 I/O boards are installed in its subrack. Up to 15 boards can be installed

in the AC 410 subrack. For the AC 460 the information from S100 I/O boards come from

separate S100 I/O subracks. Up to 5 subracks can be connected to each CI540 S100 submodule

installed in the AC 460. Please refer to the S100 I/O User’s Guide, Advant Controller 410

User’s Guide, and the Advant Controller 460 User’s Guide for more information on S100 I/O

connections.

Figure 2-17 shows an example of the connections for the AI board, DSAI 130, with 4-20mA

inputs. The connection unit DSTA 131, used together with the DSAI 130 board, is provided

with screw terminals to connect 16 analog input signals.

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Black Box IC108A Guia do Utilizador Página 35