Note what Olin says - why do this? You may have a good reason but (as noted below) RJ11 is non standard for this purpose and you are inviting compatability problems.
There is NO RJ11 serial data standard. See examples below.
Advising whatyou want to connect to and why may make this task FAR easier.
Example at end of RJ11 serial data pinouts.
Brief comment below on finding unknown pinouts.
The answer to your question is given on the blackbox page that you referenced
- Pin your own modular adapter to connect your serial equipment.
The reason that they did not connect the RJ11 connector to the DB9 is that there IS no standard way available.
The reason that they left the wires uncommitted was so that you could connect them in the way that suits you.
If you do not know what the pinout you need is, who does? (Really). What are you connecting the RJ11 circuit to? What equipment? / model? / brand? Do they provide a datas sheet or connection diagram?
Worst case you may have some equipment that has a serial circuit on an RJ11 connector that you want to connect to. In this case, the very best method is to get the manufacturer's information. If this is not available then there are ways to proceed.
Finding the pinout of a 6 pin serial connector.
This is just an overview -m knowing the equipment brand and model or, failing that, type of equipment and intended use will help geatly.
6 wire connector.
Power off. Do any wires make low resistance connections with device chassis? Label as possible grounds.
Power on. Is any line at -5 to -12V wrt chassis ground. If only one this is probably TXD. Compare to diagrams below. Any clues?
If more than one low line one may be CTS or RTS or similar. With scope on check lines on turn. Depending on equipment TXD may have data burst. RTS may toggle or play around during startup.
etc.
More on this if needed.
Examples - these are useful mainly to show how thoroughly non standard the various arrangements are.
Dell RJ11 - one implementation
H2Ns page describing their RJ11 serial pinout and connections for interfacing to other equipment
H2NS's contribution to the fun.
Here's an interesting page from Unitronics they have a number of somewhat different "arrangements"
Here's a plug pinout from one of their several arrangements - it's notable for being different from but similar to the Dell arrangement above. TXD and RXD are the same and there's some other partial similarities.
CISCO RJ45 (NB not RJ11) (from)
1 n.c. <- 7 RTS bn
2 DTR <- 4 DTR bn/wh
3 TxD <- 3 TxD gn
4 GND 5 GND bl/wh
5 GND 5 GND bl
6 RxD -> 2 RxD gn/wh
7 DSR -> 6 DSR or
8 n.c. -> 8 CTS or/wh
Note what Olin says - why do this? You may have a good reason but (as noted below) RJ11 is non standard for this purpose and you are inviting compatability problems.
There is NO RJ11 serial data standard. See examples below.
Advising whatyou want to connect to and why may make this task FAR easier.
Example at end of RJ11 serial data pinouts.
Brief comment below on finding unknown pinouts.
The answer to your question is given on the blackbox page that you referenced
- Pin your own modular adapter to connect your serial equipment.
The reason that they did not connect the RJ11 connector to the DB9 is that there IS no standard way available.
The reason that they left the wires uncommitted was so that you could connect them in the way that suits you.
If you do not know what the pinout you need is, who does? (Really). What are you connecting the RJ11 circuit to? What equipment? / model? / brand? Do they provide a datas sheet or connection diagram?
Worst case you may have some equipment that has a serial circuit on an RJ11 connector that you want to connect to. In this case, the very best method is to get the manufacturer's information. If this is not available then there are ways to proceed.
Finding the pinout of a 6 pin serial connector.
This is just an overview -m knowing the equipment brand and model or, failing that, type of equipment and intended use will help geatly.
6 wire connector.
Power off. Do any wires make low resistance connections with device chassis? Label as possible grounds.
Power on. Is any line at -5 to -12V wrt chassis ground. If only one this is probably TXD. Compare to diagrams below. Any clues?
If more than one low line one may be CTS or RTS or similar. With scope on check lines on turn. Depending on equipment TXD may have data burst. RTS may toggle or play around during startup.
etc.
More on this if needed.
Examples - these are useful mainly to show how thoroughly non standard the various arrangements are.
Dell RJ11 - one implementation
H2Ns page describing their RJ11 serial pinout and connections for interfacing to other equipment
H2NS's contribution to the fun.
Here's an interesting page from Unitronics they have a number of somewhat different "arrangements"
Here's a plug pinout from one of their several arrangements - it's notable for being different from but similar to the Dell arrangement above. TXD and RXD are the same and there's some other partial similarities.
CISCO RJ45 (NB not RJ11) (from)
1 n.c. <- 7 RTS bn
2 DTR <- 4 DTR bn/wh
3 TxD <- 3 TxD gn
4 GND 5 GND bl/wh
5 GND 5 GND bl
6 RxD -> 2 RxD gn/wh
7 DSR -> 6 DSR or
8 n.c. -> 8 CTS or/wh
The db9 connector will have the pin position numbers stamped on the front of the connector. They can be seen with a magnifier. The pins are inserted from the rear of the connector into the appropriate pin hole. Care should be taken to insert the correct pins as they can not be removed without a removal tool. These adapters work well, I have used them for RS232 many times before. As far as the pin out of the RJ11 you need to see what device it connects to and which pins correspond to the db9. The standard db9 pin out can be either a male or female connector and also DTE or DCE. You need to know what you are connecting to before you can determine the correct wiring.
Videos
I have an ancient 90's era SMARTBoard that uses an RS-232 over an RJ11 connector. There is almost no documentation online about this model, let alone pinout for the data connector. (Model is SB-2/SB-3 or 300 series)
What do I need to start figuring out the pinout for this?
I've got plenty of tools, USB to serial adapters, etc. I've already made a RJ11 pigtail that I can connect to an oscilloscope, but I have no idea what i'm doing.
This image doesn't really help, but here it is anyway: https://i.imgur.com/WNuGRax.jpeg
Full album: https://imgur.com/a/j5eAqOV
Edit: I pulled the board and uploaded images to the album. There's a chip labeled MC145407 "5 Volt Only Driver/Receiver"
I've mapped the pins on the RJ11 to these pins on the IC
-
1 Rx1
-
2 Rx3
-
3 Rx2
-
4 Tx2 (-9.95v)
-
5 GND
-
6 Tx3 (+9.95v)