Rohde & Schwarz M3SR Series 4100, Service Manual, Page: 57 / 138

Comfort Control Unit (Option) - Function R&S M3SR Series 4100 HF Transceivers
1.21 6124.9007.82.01
1.3.2.6 Comfort Control Unit (Option) - Function
The R&S GB 4000C Comfort Control Unit provides the man-machine interface for local control (or re-
mote control of detached radios) and contains all necessary control and display elements. The
R&S GB 4000C is available in two basic versions: It either comes as a module forming an integral part
of the relevant radio, or as a self-contained unit for remote control.
The local-control version itself is available in several models, all containing a controller board, a front
panel board and a 5" TFT display. In addition to these functional groups, the remote-control version
(Mod. 03) features a sturdy case and its own DC/DC power supply. The control unit is functionally con-
trolled by a micro-controller. All major functions for the interface to the display and front panel board are
implemented in an FPGA. The FPGA also scans the keys of the front panel board.
General Function
The R&S GB 4000C Comfort Control Unit consists of the following main functional groups (see
Fig. 1.8):
¾ Front panel board
¾ 5" TFT display
¾ Controller board
¾ DC/DC power supply (only Mod. 03)
The front panel board contains keys, LEDs for illumination, indicator LEDs, a keyboard and a rotary
knob. For readability in dark ambience the markings of the keys are illuminated. All indicators and the
illumination can be dimmed down. The rotary knob is used to choose between a number of provided
selections depending on the key context and to support the tuning function. The front panel board is
controlled by the controller board.
The 5" TFT display is used for displaying the operating modes, parameters and equipment status. It is
controlled by an LCD controller. The LCD controller includes a 40-kByte frame memory which is
sufficient for 4 bits / pixel and the size of the display. With Mod. 02 and Mod. 03 of R&S GB 4000C, the
display is powered by a voltage of 7.5 VDC. The supply voltage for Mod. 50 is 9.5 VDC. The display
has a resolution of 320 pixels x 234 lines. The display is provided with a CCFL (Cold Cathode
Fluorescent Lamp) back light. The brightness of the back light and the display contrast are user-
controllable.
The controller board accommodates the micro-controller and FPGA with peripherals. The micro-
controller is in charge of controlling all parameters of the (remote) radio. For this purpose it provides
data paths between the external interfaces and the (remote) radio. The realtime clock, required to
enable distinction between warm-start and cold-start (depending on how long the unit is off), is
connected to the micro-controller via I
2
C bus. Functioning of the control unit is monitored by a system
hardware monitor. For test purposes, a test connector to the micro-controller is available. The interface
AFU (Audio Frequency Unit) is designed to receive and transmit control, voice and maintenance data
between AFU and the controller board. The LAN transceiver is used to transmit control data and receive
monitoring data as well as configuration and download data. This interface may also provide digital
voice information via LAN, which will be transferred to the AFU via the interface AFU. Serial interfaces
of the types RS232/RS422/RS485 allow the remote control of R&S Series 4000 equipment.