R-KEY-LT (HW rev. E0)

1-port ModBUS to MQTT Cloud industrial gateway

R-KEY-LT is a compact and robust Modbus gateway that converts from Modbus TCP-IP protocol to Modbus RTU/ASCII and vice versa. It supports up to 8 Modbus TCP-IP clients at the same time, with up to 10 Modbus TCP-IP servers. With this model, serial Modbus slave devices can be integrated into an existing Modbus TCP-IP network, as well as Modbus TCP-IP slave devices can be made accessible to serial masters. R-KEY-LT can be configured via web server and software. It has Vac/dc power supply on the same hardware, insulation 1.5 kVac, extended temperature range. The device can also be powered via 230 Vac power supply unit.

TECHNICAL DATA

Power supply	10..40 Vdc; 19..28 Vac
Max power consumption	1 W
Max isolation	1,500 Vac
LED indicators	Power Rx/Tx RS232/R485 Ethernet ACT/LNK
Protection degree	IP20
Operating temperature	-25..+65°C
Connections	Screw terminals, 7-way removable (5 mm pitch) 2-way removable (5 mm pitch) Front RJ45 connector (x1)
Dimensions (WxHxD)	32 x 53 x 90 mm
Weight	80 g
Case material	PC/ABS self-extinguishing UL94-V0
Mounting	DIN rail (IEC EN 60715)
Certifications	CE, UKCA, UL
COMMUNICATION
Ethernet ports	1 Fast Ethernet 100 Tx port, front RJ45
Serial ports	1 RS232 / RS485 switchable port, max baud rate 115 kbps on the connector
Supported protocols	MQTTs, HTTPs, ModBUS RTU / TCP-IP / ASCII
Operating modes	MQTT Client ↔ ModBUS RTU Master / ModBUS TCP-IP Client HTTP REST ↔ ModBUS RTU Master / ModBUS TCP-IP Client
Datalogger capacity	~59,000 total samples (≈1.86 MB cache)
FLEX (multiprotocol configuration)	Yes
Variable memory area	max 300 TAGs
Connectivity	Max 3 remote TCP-IP servers Max 128 ModBUS RTU/ASCII slave nodes (per serial port) Max 8 TCP-IP clients
SECURITY
TLS 1.2 connection	Yes
X.509 certificates	Yes
CONFIGURATION
DIP Switch (default status)	Yes
Web Server	Yes
SDD (Seneca Discovery Device)	Yes
If-Then-Else logic	Yes