Ed Verhamme replied to the topic Mayfly RS232 Compatability (TTL to RS232 adapter?) in the forum Mayfly Data Logger 4 years, 2 months ago
According to the photos of your CR1000 you were using COM4. The only true RS232 port on the CR1000 is the DB-9 RS232 port.. all of the C1 to C8 I/O are TTL voltages. So you might not need any voltage converters…. Have you tried it without them?