What is the schematic of RS232 Null-Modem cable?
To connect to a computer Ferguson receivers need a cable RS-232 null-modem cable.
It is a female-female interlaced cable 
- used for communication between two digital devices. Such devices can be eg a PC and a digital satellite tuner, two PCs, a network device such as a modem / router / switch and PC.
- used for communication between two digital devices. Such devices can be eg a PC and a digital satellite tuner, two PCs, a network device such as a modem / router / switch and PC.Cable is suitable for communication between all devices having a port input / output connector DB9M, the so-called male RS232 connector
.
Ready-made cable can be purchased at a price about 2-3 euroł, or it can be made in-house.
On both sides there are female DB-9 connectors.
The individual pins should be connected according to the scheme.