Electronic equipment

Tender description

This tender specifies the technical requirements for the replacement of specific components of the Telescope Control System (TCS) for the William Herschel Telescope (WHT). The current system is based on a Marconi servo drive system and a CAMAC crate that interfaces to the high-level VMS-based TCS. The interlock system is made of relay-based circuits. The new subsystems will replace entirely the existing CAMAC crate, Marconi servo drive systems and the interlock systems. No mechanical upgrades of the telescope are desired, however minor modifications may be accepted, for example to fit new encoders. A change of motors is not envisioned. The new model should be a distributed control system with a central computer running the main control loop. This computer will run the existing VMS-based TCS, modified to communicate with the motor controllers and PLCs via a bridge computer with appropriate software which will be provided by the ING to interface between the TCS and the new electronics. The critical part of the upgrade is to design a working solution for automatic backlash control using pairs of motors. This has to be implemented so that the top-level TCS sees the controller as a single unit. The main requirements are: 1) That the servo controllers, with automatic backlash control, have to be supplied and the control loop for backlash control for WHT main axes, existing prime focus turntable and Cassegrain turntable has to be implemented, so that motion demands from the TCS can be delivered numerically; 2) That the servo drives and PLCs must be configurable remotely via an Ethernet interface; 3) That the existing motors have to remain in operation with only the drives and some of the encoders being changed; 4) To implement software interfaces for communication between the drive systems and the bridge computer; 5) To replace the existing interlock system with one based on PLCs or dedicated electronics. The interlock system must not be controllable from the TCS system, only its status can be communicated. However, an engineering interface must be supplied for simulation and engineering modes which allows inputs and outputs of the interlock system to be overridden; 6) To replace the existing control room engineering panel and focal station local control panels; 7) To implement software interfaces between the interlock unit and the control computer according to ING specifications. Full details of the requirements can be found in the Emptoris e-sourcing platform. Further supporting documents may also be found at: https://cloudone.ing.iac.es:8081/sharing/qd01icA3V