GM DATABOX: multiple remote sites

Motorola GM DATABOX VHF — GM DATABOX without front control panel; exact scope of supply is agreed separately

Three remote points must transmit the state to one central post. As long as one dot is running, the demonstration looks simple; after connecting the others, queues, waiting and replays occur. For a GM DATABOX project, it is important to determine in advance who gets the right to transmit, how long a complete bypass lasts, and how the system handles an inaccessible node. This is the task of organizing the exchange of external means, not setting up an unknown “automatic network mode” in any radio unit.

One channel – agreed exchange procedure

For dispatching data collection, you can consider a scheme with a survey manager: the central equipment addresses the selected point and expects the provided response. The next exchange is then made. Addressing, questioning, and confirmation are related to the agreed protocol of the modem, controller, and program. Built-in management of such a network does not follow from the name GM DATABOX mark SEL5.

The proposed GM DATABOX has a VHF of 136–174 MHz and a power of 1–25 W. A radio unit without a front panel is designed for consistent embedding. The manufacturer Motorola in the documentation of the GM series distinguishes between the case configuration Databox and the type of alarm. Having five tones does not prove support for Modbus, Ethernet, RS-232 or any other application protocol that is already in use on your facility.

Read the full cycle, not just the speed of the port

For each point, the size of the request, the size of the response, the time of data preparation and the envisaged pauses are recorded. They are added waiting for a response and allowable repeated attempts. The traversal time of all points is made up of these operations; it is not determined by a single digit of the interface speed. Even a short response can be delayed if the external equipment is preparing it for a long time or waiting for another action to be completed.

For example, an enterprise may need to regularly see the status of three distributed objects. This is an example of a task, not a promise of a supported number of nodes. For each point, set the necessary freshness, then check whether the selected ligament fits into a full cycle. If the requirement is not met, change the organization of the exchange, the volume of messages or the system configuration, and not declare the expected timeline actual capabilities of the radio unit.

Cycle section	What information is needed	What is checked on the assembled system
Turning to the point	Format and addressing in an external protocol	It is the chosen node that answers.
Preparation of a response	Controller operation and data size	Received the necessary fields and condition
Waiting and repeating	Limitations and number of attempts	An inaccessible node does not delay the bypass indefinitely
Move to the next point	Service arrangements adopted	All agreed points get their turn
Receipt of unscheduled communications	Separate Channel Access Rule	No unintended simultaneous exchange

An inaccessible point should not hide the rest.

Ask to show a complete bypass during normal operation and in the absence of a response from one point. At the central post, the obtained data, the exceeded expectation and the object not yet interviewed should be distinguished. Values should not look fresh just because the program continues to display the last received entry. The visibility of the state is determined by the external application, so it is included in the requirements for the solution separately.

If you need unscheduled events, determine in advance how they are combined with a regular survey. Only those access mechanisms and queues that are confirmed by the selected modem and program are possible. It cannot be assumed that the radio unit itself will handle arbitrary simultaneous transmissions. Nor can you promise that more programmed channels will automatically produce as many data directions running simultaneously.

Coordinate equipment on both sides

The diagram should show a central post and remote nodes with radio units, modems, controllers, power supply and antenna lines. Modem manufacturer DCom This is an example of a complete radio unit, where GM DATABOX is a standalone radio unit alongside the MC13 and power supply. Its description does not confirm the presence of MC13 or its capabilities in the apparatus proposed here; it is an example of why the network composition cannot be reduced to the number of housings.

For acceptance, a log of queries and results with the time of access to each point is useful. Comparison of normal bypass, inaccessible node and agreed unscheduled exchange. Not only the radio settings are checked, but also real data on the employee’s screen. The number of nodes, modes of operation and allowable waiting are fixed according to the result of the selected project, without promising universal network capacity.

Order GM Databox for the network

The main commodity is Motorola GM DATABOX VHF. The current card indicates RUB 88,000 and availability status; actual availability and deadline are confirmed when ordering. The price refers to the item described and not to a network of central and several remote sets. Specific modems, connections, configuration, and software are agreed separately.

Specify the number and location of points, the required fields, the desired bypass period and the equipment at the ends of the line. For St. Petersburg, Yekaterinburg, Omsk, Astana or Almaty, we will coordinate the composition and delivery. A detailed task for the cycle allows you to order a system with a verifiable result: the employee sees which point is updated and where the wait arose, and not just receives several identical radio units.

Bypass points and exchange state can be seen separately

External management survey

Request to the selected point
Expectation of response
Transition to the next node

Outcome for the staff member

Data received and time marked
No response - waiting is recorded
Understand the age of the data for each point

Unscheduled messages are included only under the agreed access rule

Project organization of exchange of external funds. The GM DATABOX is shown as a radio part; the number of nodes and cycle time are not stated as embedded characteristics.

Questions before buying

Does DATABOX itself manage the survey of all points?

Network management, addressing, and transmission order must be implemented and verified by the selected external protocol, modems, and program. This is not a claimed standalone feature of any GM Databox.

Can you calculate the bypass only by the speed of the port?

You need a request, a response, data preparation, pauses, waiting and repetitions for each point. Useful cycle time is checked on the entire coordinated bundle.

see the product page – the cost of a complete network?

This is the price of the described commodity item in the current card. The number of kits, modems, power supply, antenna lines, software and work are coordinated according to the network scheme; availability is confirmed when ordering.

The main product in our catalog

Motorola GM DATABOX VHF

See the product card for the current price. availability and composition are specified. The status, options and composition are confirmed in the quotation.

Request a quote

Documentation: Motorola Professional Radio GM Series: Service Maintainability, Issue September 2000; Chapter 1 §3, printed 1-4 / PDF 12; DCom Radio Telemetry Unit MC13: Manufacturer lists MC13, GM DATABOX and power supply separately. These provisions relate to these editions; the applicability to the proposed configuration is specified separately.

All technical guides hello Motorola

Survey of remote points on a real task

For a central post in Novosibirsk, list the remote nodes, the composition of the controllers and the necessary data. If some of the points are located in the Berdsk area, specify their own terms of exchange and availability. In the application for GM DATABOX, it is important to separate the radio unit, modem, controller and program. The order of work with the inaccessible node and the permissible time for obtaining information are determined in the system task; the name of the city or one demonstration does not confirm the operation of the entire network after connecting the remaining points.