Advantech EKI-1221, User Manual, Page: 14 / 67

EKI-122X Series User Manual 6
2.1.4 Modbus ASCII
As a new extension of Modbus/RTU, the Modbus/TCP protocol defines how Modbus/
RTU messages are encoded within and transported over TCP/IP-based networks.
Modbus/TCP is just as simple to implement and flexible to apply as the original Mod-
bus/RTU. The Modbus/TCP protocol is defined by its form of encapsulation for a
Modbus request or response. That means the Modbus request or response data is
encapsulated in TCP frame that has a six-byte header in Modbus/TCP protocol.
Modbus/TCP enables the use of Modbus messaging in an Intranet running the TCP/
IP protocols. Modbus/TCP is most commonly used for Ethernet attachment of PLC’s
or I/O modules to other simple field buses or I/O networks.
2.2 Specifications
Specifications Description
Interface I/O Port

EKI-1221: 2 x RJ45 + 1 x RS-232/422/485

EKI-1221I: 2 x RJ45 + 1 x RS-232/422/485

EKI-1221CI: 2 x RJ45 + 1 x RS-422/485

EKI-1222: 2 x RJ45 + 2 x RS-232/422/485

EKI-1222I: 2 x RJ45 + 2 x RS-232/422/485

EKI-1222CI: 2 x RJ45 + 2 x RS-422/485

EKI-1224: 2 x RJ45 + 4 x RS-232/422/485

EKI-1224I: 2 x RJ45 + 4 x RS-232/422/485

EKI-1224CI: 2 x RJ45 + 4 x RS-422/485
Power Connector Terminal block
Physical Enclosure Metal with solid mounting hardware
Installation DIN-Rail and Wall mount
Dimensions
(W x H x D) EKI-1221/1222: 37 x 140 x 95mm (1.46" x 5.51" x
3.74")
EKI-1224: 55 x 140 x 95mm (2.17" x 5.51" x 3.74")
LED Display System LED Power 1, Power 2, Status
Port LED LAN: Speed, Link/Active
Serial: Tx, Rx
Environment Operating
Temperature EKI-1221/EKI-1222/EKI-1224: -10°C ~ 60°C (14°F ~
140°F)
‘CI’ & ‘I’ models: -40°C ~ 70°C (-40°F ~ 158°F)
Storage
Temperature -20°C ~ 80°C (-4°F ~ 176°F)
Ambient Relative
Humidity 5 ~ 95% RH
Ethernet
Communications Compatibility IEEE 802.3, IEEE 802.3u
Speed 10/100 Mbps
Port Connector 8-pin RJ45
Protection Built-in 1.5 KV magnetic isolation