Chapter 1: Getting Started
Page 1–11
S
tride
®
MB Gateway User Manual
–
1st Edition Rev. E – August 2020
Operation
The
STRIDE
® Modbus Gateway may be configured to function in Transparent Mode or Agent Mode.
Transparent Mode is a simple protocol bridge. Modbus TCP packets that arrive at the gateway
Ethernet port will be translated to Modbus RTU or Modbus ASCII and transmitted out the
appropriate serial port. Likewise, communications arriving at the serial port will be translated to
Modbus TCP and transmitted out the Ethernet port. Data simply passes across the gateway.
Agent Mode is a valuable feature of the
STRIDE
® Modbus Gateway. The Agent can be configured
to poll specific Modbus data addresses at the serial or Ethernet nodes and store that data into
gateway shared memory. If a Modbus query comes in for one of those data points, the gateway
will immediately respond with the data it has stored and thereby respond much faster than it
would if it had to forward that request and wait for the response.
Transparent Mode
Client
Sl
av
e
TCP
Gateway RTU or ASCII
Server
Mast
er
Modbus quer
y
Modbus response
Modbus response
Modbus quer
y
Server
Master
TCP
Gateway RTU or ASCII
Client
Slave
Modbus quer
y
Modbus quer
y
Modbus response
Modbus response
Agent Mode
Client
Slave
TCP
Gateway
RTU or ASCII
Server
Mast
er
Gateway responds
Modbus quer
y
Cached
data
Modbus response
Modbus quer
y
Modbus response
Modbus quer
y
Modbus response
Modbus quer
y
with cached dat
a
Server
Master
TCP
Gateway
RTU or ASCII
Client
Slave
Cached
data
Modbus quer
y
Gateway re
sponds
Modbus quer
y
Modbus response
Modbus quer
y
Modbus response
Modbus quer
y
Modbus response
with cached data
OR
OR
