What is the pinout of the two RJ-11 Modbus jacks? I know it's RS-232, just don't know where Rx, Tx, Ground and Power (I know it has power ...) are located.
Next question -- do y'all make an RS-232 DB-9 female to RJ-11 cable that is properly wired?
Here is a PDF of the pinouts of the 3 RS232 comm jacks...
http://dl.dropbox.com/u/1641463/ClassicCommJacks_Rev-.pdf
This will end up on our website, but for now it's on dropbox.
BTW, our baud rate is 19.2 K and the standard is 9600 for default, but one will
be able to change the baud rate using the MNGP eventually.
The top connector is for the Classic's own MNGP Remote and the middle/slave
jack is for connecting to a slave Classic OR to another MNGP.
This little connection drawing below assumes that each Classic has an MNGP Remote
plugged into its MNGP port jack, but it is another RS232 port if needed.
The MNGP port jack on the Classic uses the 2 otherwise unused pins on the
6 pin phone cable to drive 2 of the 3 LEDs on the MNGP.
MASTER CLASSIC CLASSIC 2 CASSIC 3 CLASSIC 4 ETC....
[MASTER SLAVE] ------> [MASTER --> SLAVE] -------> [MASTER --> SLAVE] -------> [MASTER --> SLAVE] ---> External MNGP, etc...
boB
boB,
It looks like the "Master" connection is actually for talking to the Classic as a "Slave" device? That is, the Modbus master (my box) connects to the Classic via the "master" jack, which then provides daisy-chaining to all of the slave devices which are connected to Classic via its "Slave" jack.
So, I connect my end's Tx to pin 3 (Rx), Rx to pin 4 (Tx) and signal ground to pin 6 (GND) on the "Master" jack, set the baud rate to 19.2K and I'm golden? There isn't a square pad indicate pin 1, so I'm guessing on the pin numbering.
Also, looking at the schematic, it looks as if "Classic #1" has its "Slave" jack connected to "Classic #2"'s "Master" jack that I've got +9VDC connected to ground, since both Classics should share the same ground reference.
Quote from: tallgirl on March 15, 2011, 12:42:45 AM
boB,
It looks like the "Master" connection is actually for talking to the Classic as a "Slave" device? That is, the Modbus master (my box) connects to the Classic via the "master" jack, which then provides daisy-chaining to all of the slave devices which are connected to Classic via its "Slave" jack.
The name "MASTER" and "SLAVE" doesn't really mean much except that MASTER is the Goes-Inna and the SLAVE is the Goes-Outa, for daisy
chaining. i.e. As long as the Classic does not have another Classic connected to its MASTER jack, then it IS the master and the slaves follow.
Each port is bi-directional and for reading or writing to a Classic via modbus, it doesn't matter which one you connect to.
Quote from: tallgirl on March 15, 2011, 12:42:45 AM
So, I connect my end's Tx to pin 3 (Rx), Rx to pin 4 (Tx) and signal ground to pin 6 (GND) on the "Master" jack, set the baud rate to 19.2K and I'm golden? There isn't a square pad indicate pin 1, so I'm guessing on the pin numbering.
Also, looking at the schematic, it looks as if "Classic #1" has its "Slave" jack connected to "Classic #2"'s "Master" jack that I've got +9VDC connected to ground, since both Classics should share the same ground reference.
Remember that a phone plug usually reverses so the MASTER jack is reversed from the SLAVE (and MNGP) jacks.
So, picking on the middle (SLAVE/OUT) jack's +9V pin, it goes to No-Connect on the bottom (MASTER/IN) jack of
the next Classic.
And by the same reasoning, the middle jack's GND connects to the bottom jack's GND. TX to Rx and RX to TX
I purposely did not show pin numbers because I always get it wrong. Seems like getting phone jacks to connect
and reverse properly is ALWAYS a pain ! Rest assured I ~DID~ get things wrong at first ! I usually do.
boB