Operating instructions

16 1892 1210 - ST500 Transmitter Operating Instructions - v2.12 / May 2007
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)