Yokogawa SAI143-H53/STA4D-00 Analog Input module (Current input)

Overview

The SAI143-H53/STA4D-00 is a current input module designed for ProSafe-RS systems, supporting HART communication. It features 16 isolated channels for 4 to 20 mA input signals and supports dual redundancy. Each channel includes a built-in power supply function for HART devices.

Standard Specifications

Current Input Module

This module receives 4 to 20 mA signals from the field and can be used in a dual-redundant configuration.

Item	Specifications
Model	SAI143 (*1)
Number of Input Channels	16 channels, module isolation (*5)
Rated Input Range	4 to 20 mA
Permissible Input Range	0 to 25 mA
Input Impedance (Power-ON)	250 Ω + Current value
Input Impedance (Power-OFF)	500 kΩ minimum
Rated Accuracy	SAI143-H: ±16 µA (0.05 to 23 mA) (3) (4)
Data Update Frequency	40 ms
Temperature Drift	±16 µA/10 °C
Transmitter Power Supply	16.15 V min (at 20 mA), 26.4 V max (at 0 mA), 25 mA current limit
Withstand Voltage	1.5 kV AC between input signal and system (*2)
Max. Current Consumption	5V: 320 mA, 24V: 550 mA
Weight	0.34 kg (Clamp terminal or MIL cable), 0.39 kg (Signal cable adapter)
External Connection	Pressure clamp terminal, MIL cable, Dedicated signal cable
Transmitter Power ON/OFF	Available (2-wire setting, all channels simultaneously) (*7)
PRM Support	Available (SAI143-H)

Notes:
(*1) No Zener barriers allowed; use isolation barriers in intrinsic safety systems.
(*2) 500V AC when using dedicated signal cable.
(*3) ±32 µA (for input range under 0.05 mA, Style Code S3 or later).
(*4) Accuracy for Style Code S3 or later: ±16 µA (0.05–23 mA), for S2 or earlier: ±16 µA (1–23 mA).
(*5) When operating above 60°C, channel availability may be restricted. See “ProSafe-RS Outline of I/O Modules.”
(*6) Max voltage drop in input protection: 0.45V, input impedance varies from 272.5 Ω (20 mA) to 362.5 Ω (4 mA).
(*7) Function resets alarm states in Fire & Gas devices by turning off transmitter power in 2-wire settings. (Supported in R4.03.00 and Style Code S4 or later.)

HART Communication Specifications

The SAI143-H53/STA4D-00 supports HART 5.7 protocol, allowing communication with HART 5, 6, and 7 devices. However, only one HART device can be actively communicated with at a time due to a single HART modem.

Function	Description
Communication Mode	Serial half-duplex, start-stop synchronization (1 start bit / 8 data bits / odd parity / 1 stop bit)
Applicable Standard	HART Protocol Revision 5.7 (*1)
Transmission Speed	1200 ±2 bps
Modulation	Binary phase-continuous FSK (1 = 1200 Hz ±1%, 0 = 2200 Hz ±1%)
Frame Length	5 to 267 bytes
Error Detection	Longitudinal/vertical parity
Response Time	Max. 28 characters (256.7 ms)
No Response Timer	33 characters (305 ms) for primary, 41 characters (380 ms) for secondary
Bus Monitor	8 characters (75 ms)
Response Window	20 ms

Model and Suffix Codes

Model: SAI143-H53/STA4D-00

Description: Analog Input Module (4 to 20 mA, 16 channels, module isolation)

Suffix Codes

-H: With HART communication [Release: R1.02.00] (*1)
(1: For dual-redundant pressure clamp terminal block, do not use STA4D-0 S1.)
5: For pressure clamp terminal block or MIL cable with no explosion protection
3: With ISA Standard G3 and temperature range (-20 to 70 ºC)

Option Codes

/A4D00: *With dual-redundant pressure clamp terminal block for analog (3) [Model: STA4D-00](3: For dual-redundant configuration, order an additional module with the same specifications but without option codes.)