Comtech EF Data SDM-300A - Manual (Page 8)

SDM-300A Satellite Modem Revision 6
Preface MN/SDM300A.IOM
iv
2.2 Decription of the Modulator .......................................................................................................................2–5
2.2.1 Theory of Operation .............................................................................................................................2–6
2.2.2 Theory of Modulation Types.................................................................................................................2–7
2.3 Description of the Demodulator ................................................................................................................2–8
2.4 Description of the Decoder ......................................................................................................................2–10
2.5 Description of the Interface .....................................................................................................................2–11
2.5.1 Available Interfaces............................................................................................................................2–13
2.5.2 Plesiochronous/Doppler/Buffer...........................................................................................................2–13
2.5.3 Closed Network..................................................................................................................................2–14
2.5.4 Open Network ....................................................................................................................................2–14
2.6 Backward Alarm Theory and Connections.............................................................................................2–15
CHAPTER 3. INSTALLATION/UPGRADES.....................................................................................................3–1
3.1 Unpacking....................................................................................................................................................3–1
3.2 Installation...................................................................................................................................................3–2
3.3 Software and Hardware Installation/Upgrades.........................................................................................3–4
3.3.1 Overhead Interface PCB Installation....................................................................................................3–4
3.3.2 Hardware Upgrades .............................................................................................................................3–6
3.4 Reed-Solomon PCB ....................................................................................................................................3–6
3.4.1 Unpacking ............................................................................................................................................3–6
3.4.2 Installation............................................................................................................................................3–6
3.5 Turbo Codec Installation............................................................................................................................3–8
3.5.1 Unpacking ............................................................................................................................................3–8
3.5.2 Installation............................................................................................................................................3–9
3.6 Duplex Reed-Solomon Codec Installation..............................................................................................3–13
3.7 Data I/O Interface Connector (J8) Removal/Installation ........................................................................3–17
3.7.1 Data I/O Connector (J8) Removal......................................................................................................3–17
3.7.2 Data I/O Connector (J8) Installation...................................................................................................3–18
3.8 Hardware Upgrades ..................................................................................................................................3–20
3.8.1 Main PCB Firmware Chips.................................................................................................................3–20
3.8.2 Overhead Interface PCB ....................................................................................................................3–22