Operating instructions

1892 1211 - SR500 Receiver Operating Instructions - 2.10 / May 2006 13
APPENDIX: TTL TO RS232 ADAPTOR
Many PCs do not require true RS232, and will work with the simple adaptor of Figure 3.
The transistor used must have a gain of at least 30.
Figure 3 - Simple programming adaptor
Figure 4 shows the circuit of an adaptor providing true RS232 for readback when
programming a unit.
Figure 4 - Programming adaptor (True RS232)