SoftPLC’s DH+/RIO Smart Gateways provide protocol conversion between Allen-Bradley Data Highway Plus (DH+) and/or Remote I/O (RIO) “blue-hose” networks and Ethernet/IP, ModbusTCP, DF1, Modbus RTU, and other networks.

Smart Gateways are ideal for staged migration from devices using older, proprietary networks to new devices using Ethernet communications, combining data from multiple networks to a single Ethernet/Internet/Cellular channel for data analysis or to other high-level systems, plus many other applications.

  • (4) GB port Ethernet switch plus (1) GB Ethernet port, user-configurable protocols
  • (1) A-B “blue-hose” port (user configurable for DH+, A-B RIO Scanner, A-B RIO Adapter)
  • (1) RS-485 port (user configurable for Modbus or ASCII)
  • (2) USB 2.0 ports (user configurable for DF1, Modbus, ASCII)
  • (2) optional factory installed communication ports (“blue-hose” or RS-485)
  • Up to 100M words data registers
Ordering Information

NeoPAC Gateways use TOPDOC NexGen software for configuration and troubleshooting. A free TOPDOC NexGen license is included with your first SoftPLC purchase, see the Offers Tab.

  • Specify the communication capacity using RT Size (RT Size button describes the options).
  • There are 3 factory configured Option Ports.  One is A-B Data Highway Plus (DH+) or Remote I/O (RIO).  You can add 2 ports in any mix for DH+/RIO or RS-485.
  • You can also select Extended Temperature operation in the Hardware Options.

This assembly is base functionality. Other options are available such as WiFi, email, and more. To configure a Smart SoftPLC with other options, select model SMS4.


Options:  Your selections are appended to the part number (SKU), separated by dashes in the order listed below (if applicable).

RT Size: LT, 1K, 2K, 8K
Smart Option Ports: BH-None-None, BH-BH-None, BH-BH-BH, BH-485-None, BH-BH-485, BH-485-485
Hardware Options: No HW Options, Ext Temp
Weight: 2 lbs
Dimensions: 5 × 12 × 5 in
  • A-B PLC Upgrade Incentive OfferFree programming/configuration software with your company’s first purchase of a SoftPLC PAC or Gateway! Simply add TOPDOC NexGen to your cart, and use coupon code “FreeTDNG” at checkout.
  • With your 1st purchase of TOPDOC PLC-2, PLC-5 or PLC-3, receive a $1000 discount on a new Smart or NeoPAC SoftPLC controller or Gateway.  Simply add your selected Smart/NeoPAC to your cart, and use coupon code “ABPLCUpgrade” at checkout.  (Free TOPDOC NexGen offer above also applies!)



SMG4-A1: DH+/RIO Smart Gateway

A-B DH+/RIO Smart Gateway

Product Specifications Data Sheet | Specifications | More info…


About RT Size

RT Size is a SoftPLC license setting that determines communication driver maximums.  RT Size only applies if you are using:

  • ModbusTCP Master:  # of Server Connections
  • Ethernet/IP:  # of Connection Bytes
  • A-B DH+/RIO:  # of Logical Racks
  • Tealware Local I/O: # of Discrete I/O (largest of 2 values)
Which RT Size should I choose?  

Select Lite (LT) if you are not using the protocols above. Use the table below to determine the RT Size needed for your application.

RT Size MBTCP Enet/IP  A-B Racks I/O
LT 2 64  1 128
1K 16 512  8 1024
2K 32 1024 16 2048
8K 127 4096 64 8192
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