OG_MU-4-434_v10e Circuit Design, Inc.
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OPERATION GUIDE
4.1.4 The link parameters
In order to transmit and receive data, the MU-4 has the following link related parameters.
Link parameters can be specified easily with commands, and they can be changed each time data is sent.
In addition, if the source station, relay station, and target station do not all use the same channel, no link will be
made.
1. UI: User ID, 16-bit, 0000h to FFFEh (0000h is the ID for testing, and FFFFh cannot be used)
The User ID is an ID given to the MU-4 user for identification of the user system. Communication is not
possible unless all equipment within the user system is set with the same User ID. If a user configures
multiple systems, use the Group ID for identification. The User ID setting command is ‘@UI + User ID +
password’. The product default User ID is 0000 and this can be used as it is when no particular User ID is
required. However, we recommend that you set a User ID to prevent radio interference within a given area.
If you require a User ID, please contact Circuit Design, Inc. The 16 User IDs listed in the explanation of User ID
command can be used freely.
2. GI: Group ID, 8-bit, 00h to FFh
The Group ID is an ID to identify the group within the user system. Set the same Group ID for all equipment
within the group. Maintain Group IDs as identification numbers when building other systems. The setting
command is ‘@GI’.
Please contact Circuit Design, Inc. in cases where use of Group IDs is insufficient and you require other User
IDs.
3. EI: Equipment ID, 8-bit, 01h to FFh (FFh is a special operation)
The Equipment ID is an ID for identification of each radio unit. At the source station, enter the Equipment ID of
the target station at the end of the route information or as the Destination ID to which to transmit data.
At the target station, the Destination ID included in the received packets is automatically compared with the local
station EI. The setting command is ‘@EI’.
4. DI: Destination ID, 8-bit, 00h to FFh (00h and FFh are special operations)
This is used to specify the Equipment ID of the target station in a system not using relay stations. The setting
command is ‘@DI’. If 00 (DI = 00h) is specified as the Destination ID and data transmit command 1 is issued, all
equipment within the same group receives the data at the same time, irrespective of the Equipment ID
(Broadcast). If DI = FFh is specified, the data is sent but no station will receive it.
5. RT: Route information
This indicates the route to the target station.
The route information lists the Equipment IDs of the relay stations and the Equipment ID of the target station in
the route register or data transmit command character string. The route information is used with data transmit
commands 2 and 3. There are two ways to transmit data as follows.
Transmission based on route information set in the route register with the ‘@RT’ command
Transmission with the route information entered directly in the data transmission command
If only one station is specified in the route information, that station is the target station.
6. Channel
If all stations in a system are not set to the same channel, no link will be made.
4.1.5 Conditions for establishing a link
A link is established for communications when the following conditions are met simultaneously.
1. There are no errors in the received packet
2. The User ID and Group ID match
3. The Equipment ID specified in the route information or Destination ID and the Equipment ID of the target station
match
4. The channel used is the same
