SMC EX600 SI Units (Communication Modules)
SMC EX600 SI Units (Communication Modules)
The SI unit is the communication head of the EX600 manifold - one per system, and the single part that sets your network protocol. Pick your protocol and output polarity below, and the rest of the manifold stays the same.
An EX600 SI unit (serial interface unit) is the communication module that connects an EX600 valve manifold to your PLC's fieldbus or industrial Ethernet network. It performs the network communication and switches the solenoid valve outputs on and off. Every EX600 manifold uses exactly one SI unit, and it is the only protocol-specific part on the manifold - all I/O modules, end plates, and valve plates are shared across protocols. To change networks, you change the SI unit; nothing else on the manifold has to change.
A single SI unit drives up to 32 valve solenoid outputs and up to 9 add-on I/O units, for as many as 1024 total I/O points. Enclosure is IP67 in a complete manifold assembly; units carry CE marking and UL recognition.
How to Read an EX600 SI Unit Part Number
Every EX600 SI unit follows the same pattern. Read it left to right to know exactly what a unit is:
Protocol code (2nd block)
| EN | EtherNet/IP |
| PN | PROFINET |
| EC | EtherCAT |
| PR | PROFIBUS-DP |
| DN | DeviceNet |
| MJ | CC-Link |
| CF | CC-Link IE Field |
| PL | POWERLINK |
| MT | Modbus TCP |
Output / variant code (3rd block)
| 1 | PNP (-COM) |
| 2 | NPN (+COM) |
| 3 / 4 | PNP / NPN - dual port (EtherNet/IP) or Conformance Class C (PROFINET, EtherCAT) |
| 7 / 8 | PNP / NPN - EtherNet/IP with IO-Link master support |
| 31 | PNP - PROFINET with IO-Link and OPC UA server |
Suffixes: A (PROFIBUS / DeviceNet), X60 (CC-Link IE Field), X26 (POWERLINK), X25 (Modbus TCP).
Example: EX600-SPN4 = SI unit, PROFINET (PN), NPN Conformance Class C (4). EX600-SDN1A = SI unit, DeviceNet (DN), PNP (1), DeviceNet suffix (A).
Shop SI Units by Protocol
Match the SI unit to your PLC network. Current-generation part numbers are listed first; PNP is the most common choice in North America.
| Protocol | Current SI Unit (PNP / NPN) | Notes | Shop |
|---|---|---|---|
| EtherNet/IP | EX600-SEN7 / SEN8 | Dual port, DLR ring, QuickConnect, IO-Link master support, web server | SEN7 (PNP) / SEN8 (NPN) |
| PROFINET | EX600-SPN3 / SPN4 | Conformance Class C. SPN31 adds IO-Link + OPC UA server | SPN3 (PNP) |
| EtherCAT | EX600-SEC3 / SEC4 | SEC1 / SEC2 also available | SEC1 (PNP) / SEC2 (NPN) |
| PROFIBUS-DP | EX600-SPR1A / SPR2A | Legacy fieldbus, still widely installed | Shop PROFIBUS |
| DeviceNet | EX600-SDN1A / SDN2A | Allen-Bradley legacy networks | SDN1A (PNP) |
| CC-Link | EX600-SMJ1 / SMJ2 | Mitsubishi CC-Link | Shop CC-Link |
| CC-Link IE Field | EX600-SCF#-X60 | Gigabit Mitsubishi network | Shop CC-Link IE |
| POWERLINK | EX600-SPL#-X26 | B&R POWERLINK systems | Shop POWERLINK |
| Modbus TCP | EX600-SMT#-X25 | Open Modbus TCP/IP | Shop Modbus TCP |
PNP or NPN - Which Output Do I Need?
PNP (-COM) - codes 1, 3, 7
Sourcing output (switches the positive supply). The most common configuration in North American and European installations. Choose PNP unless your existing controls are NPN.
NPN (+COM) - codes 2, 4, 8
Sinking output (switches the ground/common). Common in Asian-spec machinery and legacy NPN control systems. The output type must match your solenoid valve wiring.
Upgrading an older EtherNet/IP SI unit?
The current EX600-SEN7 (PNP) / SEN8 (NPN) replace the prior EX600-SEN1/SEN2 (single port) and EX600-SEN3/SEN4 (dual port). The SEN7/8 add dual Ethernet ports, DLR ring redundancy, QuickConnect (~0.5s startup vs ~10s), a built-in web server, IO-Link master module support, and EtherNet/IP Conformance Composite 18 (vs. 11 on the SEN1).
It is a drop-in swap - same mounting, unit connector, end plates, valve plates, and I/O modules. Remove the old SI unit, snap in the new one, load the new EDS file. One check before you order: the SEN7/8 carry a 1.0W-per-solenoid load rating vs. 1.5W on the SEN1, so confirm your valves draw 1.0W or less.
Need IO-Link master support?
IO-Link master modules require a newer SI unit: SEN7/8, SPN3/4, SEC3/4, or SEN3-X80. Pair them with EX600-LAB1 / LBB1 masters.
Shop IO-Link MastersWireless SI unit (EX600-W)
The EX600-WEN1 wireless master runs EtherNet/IP over a 2.4 GHz link, eliminating I/O cabling between base and remote units.
Shop Wireless UnitsFunctional safety?
For safety-rated outputs, the EX600 CIP Safety unit runs CIP Safety over EtherNet/IP to IEC 61508/62061 and ISO 13849-1.
Shop CIP SafetyEX600 SI Unit Resources
EX600 Series Catalog (PDF) | EDS / GSD Configuration Files - network description files for setting up the SI unit in your PLC programming environment.