Skip to main content

IO581: RS-232/RS-422/RS-485 Serial I/O Module

4-port serial I/O module supporting RS-232, RS-422 and RS-485, with Simulink driver blocks

IO581 is a very versatile asynchronous serial module which supports RS-232, RS-422, and RS-485 on each of its 4 ports. The module also supports very high baud rates, especially for RS-422 and RS-485. The Simulink Real-Time driver blockset for this module offers a composite Send/Receive block as well as low-level setup, send, receive, FIFO, status, and utility blocks.

  • 4 independent serial ports
  • Supports RS-232, RS-422 full-duplex, RS-485 half-duplex
  • RS-232 baud rates up to 1Mb/s
  • RS-422/RS-485 baud rates up to 10Mb/s
  • RS-422/RS-485 termination resistors can be installed for each port pair on request
Form factor mPCIe
Power requirements 0.462W @ +3.3V DC
Bus PCI Express x1, 2.0 Gen. 1 compliant
Connector(s) 4 x Sub-D9 plug
Interface type Asynchrounous serial
Number of channels/ports 4
Physical interface

Software-selectable per channel/port:

Ports 1 & 2: RS-232, RS-422 full-duplex, RS-485 half-duplex
Ports 3 & 4: RS-232, RS-422 full-duplex

See Termination for additional configuration details

Programmable baud rates RS-232: up to 1Mb/s
RS-422/RS-485: up to10Mb/s
I/O signals RS-232: TxD, RxD, RTS, CTS, GND
RS-422 full-duplex: TxD+/-, RxD+/-, GND
RS-485 half-duplex: D+/-, GND

Default configuration: RS-232 (no termination resistors installed).
Termination resistors for RS-422/RS-485 can be installed for each port pair during assembly (upon request).

UART Exar XR17V354, 16550 compatible
Transceiver Exar SP336
ESD protection ±15kV
Operating temperature -40°C to +85°C
Relative humidity 5 – 95 % non-condensing
I/O Access
Front 4 x Sub-D9 plug
Item ID Product Name Components
20581X IO581
  • 1 x IO581 I/O module 
  • Driver block library for Simulink Real-Time™
  • Installation into real-time target machine
    Note: the default configuration is for RS-232 on all four ports (no termination resistors installed). For RS-422 or RS-485, the user must install the corresponding termination resistors externally.

    Alternatively, Speedgoat can install the termination resistors for each channel pair during assembly. In this case, the serial communication protocol must be defined prior to order.

Key to X in Item ID
Please replace the X with the code number of the specific target machine into which this I/O module will be installed:

  • 7 = Unit real-time target machine
  • 8 = Baseline real-time target machine

Pricing information
We do not publish pricing information on our website. Upon request by e-mail or phone, we can provide a complete price list covering our entire product portfolio in various currencies. We recommend that you contact us to discuss your specific needs. We can then quickly provide you with a tailored quotation including technical and pricing information.


Included in delivery

  • I/O module installed into real-time target machine
  • Simulink driver blocks
  • Test models
  • Comprehensive documentation

Supported target machines


Curious how to accelerate control design innovation with a modular controller hardware setup?

Request a free
workflow demo

Have Questions?

Talk to our experts about your application requirements.