Ursalink EM500-SWL, User Manual, Page: 4 / 32

2. Downlink Payload Structure
A downlink message can be sent from gateway to sensor in order to perform some actions on
that device.
Note: the application port of EM500-SWL is 85.
Downlink Packet Example
Frame N: Set the data reporting interval as 20mins (1200s).
ff 0b ff ff 01 01
Channel Type Value Channel Type Value
ff=255
0b = 11
(Device Restart
Notification)
ff
(reserved)
ff=255
01 = 1
(Custom Format
Version)
01 = 1
(Version 1)
ff 16 61 26 a1 08 75 05 00 35
Channel Type Value
ff=255 16 = 22 (Device SN) 61 26 a1 08 75 05 00 35
ff 09 01 00 ff 0a 01 01
Channel Type value Channel Type Value
ff = 255
09
(Hardware version)
0100
(V1.0)
ff = 255
0a
(Software Version)
0101
(V1.1)
ff 0f 00
Channel Type value
ff = 255 0f (Class Type) 00 (Class A)
1 Byte 2 Bytes 1 Byte 1 Byte 2 Bytes 1 Byte
Channel1 Data1 0xff (Reserved) Channel2 Data2 0xff (Reserved)
ff 03 b0 04
Channel Type Value
ff = 255 03 (Set Reporting Interval) b0 04 => 04 b0 = 1200 (second)