I have tried to connect to it via FTDI, as well as via PL2303. In both cases, I can see the serial connection in terminal, and if I connect the ESP8266's Rx to Tx and use the Serial Monitor in Arduino IDE, my typed text is echoed as expected. This suggests the FTDI and PL2303 are working (am I correct in assuming this?)
As soon as I connect the ESP8266 to the FTDI or PL2303, the serial connections disappear. If I then disconnect the ESP 8266, the connection reappears after 2-10 seconds. The connection to the connected ESP8266 returns sporadically, whereupon I have been able to use the Serial Monitor (in Arduino IDE) to send commands to the ESP8266. Specifically, I have had the following result for AT+RST:
AT+RST
OK
ets Jan 8 2013,rst cause:2, boot mode:(3,0)
load 0x40100000, len 1856, room 16
tail 0
chksum 0x63
load 0x3ffe8000, len 776, room 8
tail 0
chksum 0x02
load 0x3ffe8310, len 552, room 8
tail 0
chksum 0x79
csum 0x79
2nd boot version : 1.5
SPI Speed : 40MHz
SPI Mode : DIO
SPI Flash Size & Map: 8Mbit(512KB+512KB)
jump to run user1 @ 1000
don't use rtc men data
This does not look like what would be expected. I have searched high and low, but have only found 2 occasions where people have asked for help about this same issue. In both cases, the OP noted that they have resolved the issue, but did not post how.
I know it sound ridiculous, but I have spent over 10 hours on this, without resolution. I have checked the connections, examined the soldering on the FTDI and PL2303, reinstalled OSX drivers several times, etc.
When the ESP8266 is connected to the FTDI or PL2303, if I connect the reset pin to ground, the serial connection appears again. Once I remove the reset pin from the ground, it disappears again. The blue led on the ESP8266 flashes twice when I do this.
Any help would be greatly appreciated. I cannot move forward with my project (an alarm system that will email me when triggered) without this component.