Analog input programmable controller PLC XGF-AD8A XGF-AD8A XGFAD8A

LS Electric XGF-AD8A | XGT Series 8-Channel Analog Input Module — 14-Bit / Voltage-Current / 0–20mA / 250μs / Screw Terminal

8-Channel Analogue Input with Per-Channel Voltage or Current Selection

The XGF-AD8A is the 8-channel voltage/current analogue input module for LS Electric's XGT PLC series. Each of the eight channels independently accepts either a voltage or a current signal — the configuration is set per channel, allowing the same module to simultaneously read a mix of voltage-output transmitters and current-loop (4–20mA or 0–20mA) sensors without additional hardware.

At 14-bit resolution, the module resolves analogue input signals to 16,384 counts across the full input span. For a 4–20mA current input representing 0–100 bar, each count represents approximately 0.006 mA — approximately 0.01 bar of resolved measurement. For a ±10V voltage input, each count represents approximately 1.22 mV. This resolution is adequate for process control, flow measurement, pressure and temperature monitoring, and level detection where the sensor signal represents a physical process variable.

The conversion speed of 250 microseconds per channel means all eight channels complete one scan in 2 milliseconds — well within the PLC cycle time requirements for standard process and machine control applications. The XGF-AD8A occupies one slot in the XGT PLC baseplate and draws power from the PLC backplane, requiring no separate external analogue power supply for its conversion circuits.

Key Specifications

Open Type — What This Means for Wiring

"Open type" indicates the XGF-AD8A does not provide electrical isolation between individual channels. All 8 channels share a common reference. This is adequate for most process control installations where all sensors reference the same electrical ground.

For applications where sensors are at different electrical potentials, floating relative to each other, or exposed to significant ground potential differences — such as measuring signals from equipment on different electrical circuits — an isolated module (such as the XGF-AD4S) is the appropriate selection.

XGF-AD8A in the XGT Analogue Module Family

FAQ

Q1: How is each channel configured for voltage or current input on the XGF-AD8A?

The input type (voltage or current) for each channel is set through the XGT PLC software (XG5000) in the module's parameter configuration screen. There are no physical jumpers or DIP switches for voltage/current selection — the configuration is done in software and downloaded to the module as part of the PLC project.

Q2: Can the XGF-AD8A read 4–20mA sensors directly?

Yes. The 4–20mA range is within the 0–20mA input range of the current input configuration. The PLC programme can scale the raw digital value to the physical process variable, accounting for the 4–20mA span. Many LS Electric programming examples demonstrate this scaling method directly in the XG5000 programme.

Q3: The XGF-AD8A shows a channel error on one input. What causes this?

Common causes: the input signal is outside the valid range (a broken 4–20mA loop reads below 4mA, which some modules flag as an error); the channel is configured for current but wired for voltage (or vice versa); the screw terminal connection is loose. Check the signal level at the module terminal with a milliammeter or voltmeter, confirm the wiring matches the configured input type, and verify terminal tightness.

Q4: How many XGF-AD8A modules can be installed in one XGT PLC system?

The number of special function modules (including analogue input modules) that can be installed depends on the CPU model. XGI and XGK CPUs support different numbers of special modules per system. Confirm the specific CPU's maximum module count from the XGT series PLC user manual for the installed CPU type.

Q5: Does the XGF-AD8A require an external power supply?

No. The XGF-AD8A receives its operating power from the XGT PLC backplane. A 24V DC external source is not required for the module's electronics. Field transmitters connected to the module may require their own loop power supply (for 4–20mA loop-powered transmitters, an external 24V DC loop supply is needed for the field circuit, not for the module itself).