Model Interpretation

SAI = Safe Analog Input - Safe Analog Input; 16 = 16 channels; 20 = Hardware Series Version; M = Standard Industrial Type. Technical Specifications

Channel Specifications: 16 isolated analog input channels. The 4-20mA signal at the site is converted to 0-4.1VDC voltage on the module side through the matching terminal base.

Resolution: 12-bit AD sampling. The measurement accuracy is ±0.1% FS. The crosstalk between channels is >60dB.

Power Supply: Dual power supply of 5VDC/35mA and 24VDC/35mA on the backplane. The overall power consumption is approximately 2W.

Input Impedance: ≥1MΩ. Each channel has surge protection of ±36VDC.

Safety Certification: TÜV SIL3, UL, CE, FM explosion-proof certification, in line with IEC61508 functional safety standard.

Operating Environment: -20℃ to +60℃, humidity 5% to 95% without condensation; size 4HP (4TE) × 3U (3HE), net weight about 350g.

Interface and Communication Configuration

Panel: LED indicators for operation, fault, and abnormal channel status;标配 blue flexible cable connecting the base terminal

Backplane： European gold finger plug-in SM/FSC system rack backplane， interacting data with the main control CPU through the internal safety bus

Site Wiring： Dedicated I/O terminal base， 16-channel 4-20mA transmitters' cables are connected to the base， and the base has a 250Ω precision sampling resistor for I/V conversion

System Architecture： Compatible with system 2oo4D voting architecture. Modules have fault-safe failure， and will not trigger interlocks by mistake.

Core Function

16-channel independent signal acquisition， AD analog-to-digital conversion， each channel can be enabled or disabled through group configuration

Real-time hardware self-diagnosis for all channels： fault identification for open circuits， short circuits， and over-range， fault information uploaded to the safety main control

Fault-safe design， default safe output when module fails， ensuring ESD interlocks do not malfunction

Electrical isolation of channels， eliminating interference from the site ground loop， single-channel failure does not affect other acquisition circuits

Cooperate with the upper Safety Builder software to complete range， alarm threshold， and interlock logic configuration. Applicable scenarios

Petrochemical refining and chemical industry ESD emergency shutdown system, oil and gas field station F&G fire and gas detection system, boiler/compressor safety protection interlock, coal chemical plant SIL level safety instrumented cabinet, power plant auxiliary equipment trip protection system.

Installation and maintenance instructions

Field instruments use shielded twisted pair cables. The shield layer is single-point grounded on the cabinet side to reduce frequency interference

Modules support hot-swappable power-on of the rack. After replacing spare parts, the system automatically downloads configuration parameters

Annual calibration of the sampling resistance of the terminal base, take measures to prevent moisture and rust of the terminals in humid environments

Do not plug or unplug the blue cable while powered on. Before disassembling and assembling, disconnect the power supply of the corresponding field instrument for the channel.