SAI143-H53/A4S00

The Yokogawa SAI143-H53/A4S00 is a 16-channel analog input module for 4-20 mA current signals in the CENTUM system. It provides channel-isolated input circuits and supports HART communication for transmitter data access. The module includes transmitter power supply functionality, individually configurable 2-wire or 4-wire inputs, and a 40 ms data update frequency.

Input Channels and Signal Processing

The SAI143-H53/A4S00 accepts up to 16 analog current input channels, with module isolation between the input signals and the system. Its rated input range is 4 to 20 mA, while the permissible input range extends from 0 to 25 mA.

The input impedance during power-on is specified as 250 Ohm plus the input current value. During power-off, the minimum input impedance is 500 kOhm. These characteristics are relevant when checking transmitter loop loading and signal behavior during module power interruptions.

HART Communication and Transmitter Configuration

The SAI143-H53 version supports HART communication, allowing compatible field transmitters to provide digital device information alongside the analog 4-20 mA process signal. This is useful for transmitter configuration and diagnostics without treating the module as a conventional digital input device.

Each channel can be individually configured for 2-wire or 4-wire transmitter connections through setting pins. The transmitter power supply provides at least 16.15 V at 20 mA and a maximum of 26.4 V at 0 mA, with an output current limit of 25 mA.

Accuracy and Electrical Characteristics

The specified rated accuracy for the SAI143-H version is +/-16 uA over an input range of 0.05 to 23 mA. Its temperature drift is +/-16 uA per 10 deg C, and the data update frequency is 40 ms.

The input signal circuit has a withstand voltage of 1.5 kV AC between the input signal and the system for one minute. Maximum current consumption is 320 mA from the 5 V system supply and 550 mA from the 24 V system supply.

Terminal Connection and Model Configuration

The /A4S00 option specifies the analog pressure clamp terminal block, identified by Yokogawa as STA4S-00. This configuration provides the terminal connection for field current signals rather than the signal cable interface adapter.

The model suffixes identify the following configuration:

Code	Specification
SAI143	4-20 mA analog input, 16 channels, module isolation
-H	HART communication
5	Pressure clamp terminal block or MIL cable, without explosion protection
3	ISA Standard G3, operating temperature -20 to 70 deg C
/A4S00	Analog pressure clamp terminal block, STA4S-00

The complete ordering code identifies a HART-capable module with the specified terminal block configuration. The -H version requires ProSafe-RS software release R1.02.00 or later for HART functionality.

Technical Specifications

Parameter	Specification
Model	SAI143-H53/A4S00
Brand	Yokogawa
Product Type	Analog Input Module
Base Model	SAI143
Communication	HART
Number of Input Channels	16
Input Isolation	Module isolation
Rated Input Range	4 to 20 mA
Permissible Input Range	0 to 25 mA
Input Impedance (Power ON)	250 Ohm + input current value
Input Impedance (Power OFF)	500 kOhm minimum
Rated Accuracy	+/-16 uA (0.05 to 23 mA)
Data Update Frequency	40 ms
Temperature Drift	+/-16 uA/10 deg C
Transmitter Supply Voltage	16.15 V minimum at 20 mA; 26.4 V maximum at 0 mA
Transmitter Output Current Limit	25 mA
Transmitter Configuration	Individually selectable 2-wire or 4-wire
Input Protection Voltage Drop	0.45 V maximum
Withstand Voltage	1.5 kV AC, input signal to system, 1 minute
Maximum Current Consumption	320 mA (5 V system); 550 mA (24 V system)
External Connection	Pressure clamp terminal block, STA4S-00
PRM Support	Available
Operating Temperature	-20 to 70 deg C
Environmental Classification	ISA Standard G3
Weight	0.34 kg

HART Communication and PRM Support

The SAI143-H supports HART communication between compatible field transmitters and the Plant Resource Manager (PRM). This provides access to digital transmitter information in addition to the analog process measurement carried by the 4-20 mA signal.

One HART device can be connected per channel. However, the module has one HART modem and can communicate with only one HART device at a time. This distinction is important when evaluating simultaneous device communication requirements.

Frequently Asked Questions

Q: Can the SAI143-H53/A4S00 connect to both 2-wire and 4-wire transmitters?

A: Yes. The module supports individually selectable 2-wire and 4-wire configurations for each channel. The connection mode is selected through the module setting pins.

Q: Does the SAI143-H53/A4S00 support simultaneous HART communication on all 16 channels?

A: No. Although one HART device can be connected to each channel, the module has only one HART modem and communicates with one HART device at a time.

Q: Is the transmitter power supply ON/OFF function available on this exact model?

A: The function is subject to hardware style and software requirements. Yokogawa specifies support from style code S4 and software release R4.03.00 onward. The supplied H53 model has style code S3, so this function should not be assumed available on this configuration.

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