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PortBloque E
The Ethernet firewall that's Modbus dedicated.

$495 USD
Made in California
Protects Modbus systems from Internet threats

PortBloque™ ("port block") E is a Modbus Ethernet firewall to protect serial control devices from unwanted Internet traffic. It performs deep packet inspection (DPI) on Modbus traffic to ensure that systems receive only the commands required for normal operations and not accidental or unauthorized commands that could lead to harmful consequences.

Two firewalls in one
PortBloque E is really two firewalls in one. It performs standard firewall functions plus advanced Modbus filtering. System and traffic activity can be sent to a syslog server for later analysis.
Evades port scanning
Stealth mode makes Modbus ports invisible from sniffing. Any probing is completely ignored, as if the packet were lost in space.
Converts Ethernet to serial 
The purpose-built firewall positions at the entry point to serial devices and supports an RS-232, RS-422, or RS-485 connection. It automatically converts Modbus TCP/IP to Modbus RTU/ASCII. No need to change the Modbus network or applications.
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 ranges, you can prevent the control device from being put into an undesired or unstable mode.
You can also control the amount of time to wait before a Modbus command can be repeated.
Key Features
PortBloque E

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 
   ■  Safeguard time between repeated commands
   ■  Access control list
   ■  Stealth mode (makes Modbus ports invisible)
   ■  Source IP, Protocol, and Port 

Ethernet-to-Serial Conversion
   ■  Ethernet
- Modbus TCP/UDP 
- Modbus RTU over TCP/UDP 
- Modbus ASCII over TCP/UDP
   ■  Serial
- Modbus RTU/ASCII

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

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

     Easy click configuration  

Buy now

PortBloque E
$495.00 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 E (quantity+shipping):