SNAP Controller and Brain Comparison

Opto 22 SNAP PAC controllers and SNAP PAC brains serve some of the same functions in your SNAP PAC System, but they also differ.
This chart compares the features of the latest PACs and brains, with minimum firmware version R10.0 and PAC Project R10.0.
Note that due to unavailable essential parts, SNAP PAC brains are obsolete as of 2022. Use R-series PACs instead.
For more details, see the PDF Form 1677, SNAP PAC Controller & Brain Comparison Chart.

  Software Standalone PACs Rack-mounted PACs Ethernet Brains (OBSOLETE) Serial Brains
(OBSOLETE)
Feature SoftPAC SNAP-PAC-S1 SNAP-PAC-S2 SNAP-PAC-R1 SNAP-PAC-R2 SNAP-PAC-EB1 SNAP-PAC-EB2 SNAP-PAC-SB1 SNAP-PAC-SB2
Runs PAC Control strategies        
Maximum PAC Control charts running at once (plus host task) 64 32 32 16 16        
   Communication
Two independent Ethernet network interfaces (two IP addresses) a        
Two switched Ethernet network interfaces (one IP address) for multi-drop configuration              
Total number of RS-232 serial ports b 2 4c 1 1 0 0 0 0
Total number of RS-485 serial ports b 1 4c 0 0 0 0 1 1
   Protocols
TCP/IP, UDP/IP    
EtherNet/IP (Allen-Bradley RSLogix systems, others)      
Modbus/TCP (slave)d      
OPC driver support f f
RESTful API          
HTTP/HTTPS          
OptoMMP memory-mapped protocol g
SNMP (network management)      
FTP server, file system      
FTP client        
SMTP (email client with authentication and attachments        
  General  
SNAP-PAC nodes for Node-RED; RESTful API          
Direct access to hard drive, network drives (Dropbox, etc.)                
Realtime clock a
Backup battery (recharges when brain has power)h  
Physical RAM (MB)
RAM available for PAC Control strategy (MB)
Battery-backed RAM (MB)
Flash memory (MB)
a
64
8
i
32
16
8
16
32
16
8
16
16
4
2
​8
16
4
2
​8
16
--
--
8
16
--
--
8
16
--
--
8
16
--
--
8
Removable data storage (microSD card slot) a 32 GB maxk 32 GB maxk 32 GB maxk 32 GB maxk        
32-bit processor a
Floating-point unit (FPU) a        
Power requirements a 8-32 VDCl
10W-11.3 W max
5.0 to 5.2 VDC
@ 1.2 to 1.5 A
5.0 to 5.2 VDC
@ 750 mA-1.0 A
5.0 to 5.2 VDC
​@ 750 mA-1.0 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%
Compatible with SNAP PAC EB (Ethernet) brains        
Compatible with SNAP PAC SB (serial) brains              
Compatible with SNAP PAC R-series controllers        
Compatible with groov EPIC         
Compatible with groov RIO         
Combination controller and I/O processorm              
Mounts on SNAP PAC I/O mounting rack       
Mounts on SNAP B-series I/O mounting rack       v          
Maximum number of modules allowed on largest rack: Any mix of 16 digital, 16 analog, and 8 serial       o o
   Digital I/O point features
Input latching      
On/off status      
Watchdog timer      
High-speed counting (up to 20 kHz)q            
Quadrature countingr            
On-pulse and off-pulse measurementq            
Frequency and Period measurementq            
TPO (time-proportional output)      
Digital totalizingq      
Pulse generation (continuous square wave, N pulses, on-pulse, off-pulse)      
   Analog I/O point features
Thermocouple linearization (32-bit floating point for linearized values)      
Minimum/maximum values      
Offset and gain      
Scaling      
TPO (time-proportional output)s      
Output clamping      
Filter weight      
Watchdog timer      
Analog totalizingt      
Rampingt      
PID logic (maximum 96 PID loops per controller or brain)      
Data logging      
Digital events,alarm events, serial events       u u
Events messaging          
UDP streaming of I/O data to host          
I/O point data mirroring and memory map copying          
a As provided by the Microsoft Windows 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 PAC firmware >=R9.4b, 8 max connections. Lower firmware, 2 max connections.
f Available with OptoOPCServer and PAC Control, through a SNAP PAC controller.
g SoftPAC includes Status Read, Status Write, and Scratch Pad memory map areas.
hModels manufactured before August 2007 and S1s with serial numbers 625653 and lower have user-replacable backup batteries. See original user's guide.
i Flash memory function implemented via a file; size is limited only by disc space
k PAC firmware 9.4a and loader 6.1a or higher. S-series with microSD & manufacture date older than 06/2014 supports maximum 2 GB microSD.
l Units with serial numbers lower than 500,000 have an 8-24VDC input voltage rating. Verify voltage on the unit's faceplate before applying power.
n For compatibility with legacy Opto 22 hardware, see Form 1693, Legacy and Current SNAP Product Comparison and Compatibility Charts.
m I/O features vary by model. For details, see form 1677, SNAP PAC Controller and Brain Comparison Chart.
o SNAP-PAC-R1s with serial numbers lower than 600,000 and all SNAP-PAC-R1-Bs; limited to 4-point digital modules per rack.
p Not supported: serial, motion control, Profibus, & Wiegand modules.
q Four-channel modules only; not high-density modules.
r Requires a SNAP-IDC5Q quadrature input module.
s Requires a SNAP analog TPO module (SNAP-AOD-29).
t Requires a SNAP PAC controller and PAC Control commands.
u Does not support serial events.
v Only applies to SNAP-PAC-R1-B (Obsolete)