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PortBloque S
The serial firewall that's Modbus dedicated.

$475 USD
Made in California
Enforces safe and secure operations

PortBloque™ ("port block") S can prevent attacks on Modbus control systems. The purpose-built firewall looks deep inside Modbus packets to ensure that systems receive only the commands required for normal operations and not accidental or unauthorized commands that could lead to harmful consequences.

Drop-in Modbus security
PortBloque S peforms advanced Modbus filtering to protect serial control devices. It installs easily on RS-485, RS-422, or RS-232 networks. It can also be used in conjunction with a standard firewall to provide strong Modbus security.
Filters anything and everything

Modbus filtering is easy!
Simply enter the Modbus device IDs and select the types of Modbus function codes you want those devices to receive.

You can select your own (user-defined) function codes too.  
By defining register and value range, you can prevent the control device from being put into an undesired or unstable mode.
Key Features
PortBloque S

Firewall Rules
   ■  Modbus deep packet inspection (DPI):
─ Device IDs:  single or group, incl. broadcast ID 
─ Function codes:  1-8, 11,12, 15-17, 20-24, 43;
                               four user-defined codes
─ Registers 
─ Values 
   ■  Bidirectional filtering  

Serial Protocols
   ■  Modbus RTU 
   ■  Modbus ASCII

Data Rate
   ■  300 to 115.2K bps (async)

   ■  RS-485 2-wire, RS-422 4-wire, RS-232
   ■  Host/Slave: 10-pin terminal block
   ■  Host, Slave, and Mgmt: DB9
   ■  LAN: RJ45 Ethernet (10/100BaseT)

Web Interface
   ■  Easy click configuration 
   ■  Login-secure levels: Superuser, User 
   ■  Dashboard for at-a-glance firewall statistics

    ■  Syslog    

Buy now

PortBloque S
$475.00 USD
I. INTERNATIONAL - To order from outside the contiguous (48) United States and International, please use the Order Request form.

o order from inside the contiguous (48) United States:

We accept payment in the form of most major credit cards, debit cards and even personal checks via our payment processing partner, PayPal – but no, you do NOT need to have an account with PayPal to pay us! You can select a quantity up to 5 from the dropdown and click on the 'Buy Now' button. Orders ship within one week via UPS Ground.
To order a quantity greater than 5, please use the Order Request form.
PortBloque S (quantity+shipping):