Trigger Readout Board v3 Platform

The main motivation was to design a platform consisting of hardware, firmware and software out of which readout systems of various scale requesting distributed data processing could be constructed. Thus, the key features of the TRB platform are: scalability, extensibility, flexibility and reconfiguration. Those points were achieved by the design of a system based on interconnected in a tree architecture, identical base modules with extension cards (Add-on boards) for various measurements (for example ADC). Such modules provide vital functionality like signal digitization with feature extraction, data transmission, control mechanisms and hub features, which allow to introduce further modules and expand the system. However one should keep in mind that extension should preserve the performance characteristics, while the number of modules increases. The additional modules are needed in order to introduce a higher number of input channels, a new type of measurement or data processing that is not provided by the base module. Such approach led to creation of a fully universal platform for a broad range of measurement systems, which is reflected by the amount of various users and high demand for this solution.

 

Photo1: TRBv3 board equipped with various Add-on modules [trb.gsi.de]

The system is composed out of two main logical elements: endpoints and hubs. They both can exist as hardware components or as firmware modules. The endpoints are the elements in the system that perform signal digitization and some kind of processing, which results in generated data. Each endpoint has to be connected to one port of the hub, through which it can receive readout requests and control commands from the central controller. Through the hub connection, the endpoint can also transmit its data portion. Each module connected to a hub acts as an endpoint to that hub. Such approach masks the complexity of the system and returns it as a really scalable platform. One can always connect a new hub to an existing and therefore, open several additional slots for new endpoints (which, in turn could also be hubs etc.).

 

Scheme1: Schematic view of the system architecture

 

The elements of the systems are composed in a tree hierarchical architecture (Scheme 1). There is one root module which is the central hub. From this point several branches can be driven, each consisting of hubs and endpoints, which are leafs. The central hub distributes the readout requests coming from the central controller and control messages from the control module. Those messages flow in downstream direction, from the source to the endpoints. The responses generated by the endpoints flow in upstream direction. As the endpoints are treated as independent from each other, there is no communication channel between them in a horizontal direction. The hubs can distribute messages from its root to its endpoints or collect messages from the endpoints and forward them to the root.

The TRB platform provides a base module, which can act as a hub and/or as an endpoint. Depending on the loaded firmware, the board can realize all the above described functions: contain endpoint modules that provide data, an instance of the hub, a control and a central controller modules. It means that the smallest system can be built out of a single board, which is convenient for small setups. This high flexibility in the usage of the base module could be possible thanks the FPGA devices. While the hardware remains the same and provides the infrastructure, the exact function of a board is defined by the loaded firmware.

The project is developed by a collaboration of various scientific institutes mainly: Jagiellonian University, Frankfurt University and GSI GmbH Darmstadt: www.trb.gsi.de

 

 

 

Contact person:

Grzegorz Korcyl

grzegorz.korcyl (at) uj.edu.pl