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SNAP PAC Controller Comparison

Opto 22 SNAP PAC programmable automation controllers are available in three forms:

  • Standalone PAC (S-series)
  • Rack-mounted PAC (R-series)
  • Software-based PAC for PC-based control (SoftPAC)

This chart compares features for the latest SNAP PACs, with minimum firmware version R10.0 and PAC Project software R10.0.

For additional information, see the PDF, SNAP PAC Controller Comparison Chart.

  Software Standalone Rack-mounted
Feature SoftPAC SNAP-PAC-S1
Maximum PAC Control charts running at once 64 32 32 16 16
Ethernet (UDP/IP, 10/100 Mbps) x x x x x
Two independent Ethernet network interfaces a x x x x
Number of RS-485 serial ports b 1 4c 0 0
Number of RS-232 serial ports   2 4c 1 1
EtherNet/IP (Allen-Bradley RSLogix systems, others)   x x x x
Modbus/TCP (slave)   x x x x
OPC driver support x x x x x
RESTful API   x x x x
HTTP/HTTPS   x x x x
OptoMMP memory-mapped protocol xd x x x x
SNMP   x x x x
FTP server, file system   x x x x
FTP client x x x x x
SMTP (email client, authentication, attachments) x x x x x
Supports Node-RED via SNAP-PAC nodes and RESTful API   x x x x
Direct access to hard drive & network drives (Dropbox, etc.) x        
Real-time clock a x x x x
Backup battery (recharges when PAC has power)   x x x x
Physical RAM
RAM available for strategy
Non-volatile or batter-backed RAM
Flash memory
Data storage space
64 MB
8 MB
32 MB
16 MB
8 MB
16 MB
~2.5 MB
32 MB
16 MB
8 MB
16 MB
​~2.5 MB
16 MB
4 MB
2 MB
8 MB
​~2 MB
16 MB
4 MB
2 MB
8 MB
​~2 MB
Removable data storage (microSD card slot) a 32 GB max 32 GB max 32 GB max 32 GB max
32-bit processor and floating-point unit (FPU) a x x x x
Compatible with SNAP PAC EB (Ethernet) brains x x x x x
Compatible with SNAP PAC SB (serial) brains   x x    
Compatible with groov EPIC and groov RIO x x x x x
Combination controller and I/O processor       x x
Power requirements a 8-32 VDC
10 W-11.3 W max
8-32 VDC
​10 W-11.3 W max
5.0 to 5.2 VDC
@ 1.2-1.5 A
5.0 to 5.2 VDC
​@ 1.2-1.5 A
Operating temperature (degrees C)
Storage temperature (degrees C)
a -20 to 60
-40 to 85
-20 to 60
​-40 to 85
-20 to 60
​-40 to 85
-20 to 60
​-40 to 85
Humidity (non-condensing) a 0-95% 0-95% 0-95% 0-95%
a As provided by the Microsoft Windows-based computer SoftPAC runs on. 
b SoftPAC cannot communicate through serial ports on the PC.
c Serial ports are software configurable for RS-232 or RS-485.
d SoftPAC includes Status Read, Status Write, and Scratch Pad areas of the memory map.
e Function of Flash memory is implemented via a file; size is limited only by available disk space.
f Obsolete part