Configured for mixed analog signal acquisition and output control in the ABB AC500 system, the ABB AX521 1SAP250100R0001 (AX521 Analog Input/Output Module) provides 4 analog inputs and 4 analog outputs with 12-bit or 12-bit plus sign resolution.

Model and Function

The AX521 is an S500 analog I/O module for the ABB AC500 PLC platform. ABB documentation identifies the module as a combined 4 AI / 4 AO device. Analog input signal types include voltage, current, and supported temperature sensors. Analog outputs support voltage and current ranges.

The supplied part number is 1SAP250100R0001. The module is identified in the supplied product information as discontinued by the manufacturer.

Hardware Specifications

ABB documentation specifies four analog inputs and four analog outputs for AX521. The module supports 12-bit resolution, with 12 bits plus sign for bipolar voltage ranges. ABB also specifies 24 V DC process voltage and 0.150 A minimum module consumption on the process-voltage supply.

ABB AC500 Analog I/O Architecture

The AX521 operates as an S500 I/O module connected to the AC500 control system through the extension bus interface. ABB documentation identifies the fieldbus connection as being provided through the AC500 CPU or communication interface modules. The module supply is provided internally through the I/O bus interface.

The four analog input channels can be configured for supported voltage, current, and temperature measurement functions. The four analog output channels provide voltage or current signal generation. This mixed-channel arrangement allows analog acquisition and output functions to reside in a single S500 module.

For analog signal integrity, ABB specifies a maximum analog line length of 100 m when the conductor cross section is greater than 0.14 mm2. The module also provides per-module potential isolation and reverse-polarity protection.

I/O Signal Configuration

Analog Input Channels

• 4 analog input channels.
• 0 to 10 V input range.
• -10 to +10 V input range.
• 0 to 20 mA input range.
• 4 to 20 mA input range.
• Supported temperature input functions include Pt100, Pt1000, and Ni1000.
• Resolution is 12 bits or 12 bits plus sign depending on the configured signal range.

Analog Output Channels

• 4 analog output channels.
• -10 to +10 V output range.
• 0 to 20 mA output range.
• 4 to 20 mA output range.
• Voltage-output loading capability is specified at a maximum of +/-10 mA.
• Current-output burden is specified up to 500 ohm.

Ordering Information

• 1 x ABB AX521 Analog Input/Output Module
• Part number: 1SAP250100R0001
• Series: AC500 / S500
• Product family: Analog S500 I/O
• Product classification: Analog I/O module
• Separate terminal bases or mounting accessories are not identified in the supplied product information.
• The compatible terminal base should be verified against the intended AC500 installation before replacement.

Field Installation Guidelines

Module Mounting

• Install the AX521 on the specified AC500/S500 mounting and terminal arrangement.
• Confirm the module position and I/O configuration before energizing the system.
• Do not force the module onto an incompatible base or bus connection.
• Inspect the bus interface and terminal contacts before installation.

Analog Wiring

• Separate analog signal cables from motor, contactor, and high-current switching conductors.
• Maintain the existing shield termination method used by the control cabinet.
• Use appropriate twisted and shielded cable for low-level analog signals.
• Keep analog wiring within the specified line-length limitation where applicable.
• Check polarity before applying voltage or current signals.

Commissioning

• Verify the configured input range against the connected field transmitter or sensor.
• Verify the output range against the receiving actuator or analog device.
• Confirm the 24 V DC process supply before enabling the module.
• Check the PLC configuration for the correct AX521 module type and channel assignment.

Frequently Asked Questions

• How many analog inputs does AX521 provide?

  AX521 provides 4 analog input channels. ABB specifies voltage, current, and supported temperature measurement configurations for these inputs.

• How many analog outputs are available?

  The module provides 4 analog output channels. Supported output ranges include -10 to +10 V, 0 to 20 mA, and 4 to 20 mA.

• What is the AX521 resolution?

  AX521 uses 12-bit resolution. Bipolar ranges such as -10 to +10 V use 12 bits plus sign, while unipolar ranges use 12 bits.

• What supply voltage does the module use?

  The ABB technical data specifies a 24 V DC process voltage. Minimum module consumption is listed as 0.150 A before additional load considerations.

• Does AX521 support 4 to 20 mA signals?

  Yes. ABB lists 4 to 20 mA as both an analog input and analog output configuration for AX521.

• What is the maximum analog cable length?

  ABB specifies a maximum line length of 100 m for analog lines when the conductor cross section is greater than 0.14 mm2.

• Is the AX521 a mixed I/O module?

  Yes. AX521 combines 4 analog inputs and 4 analog outputs in one S500 module. ABB lists it as an analog S500 I/O device for AC500.

• Can AX521 be treated as a generic analog I/O card?

  No. It is designed for the ABB AC500/S500 architecture. The bus interface, terminal arrangement, configuration, and supported firmware should be checked before substitution.