Dear experts;

İ am new for programing with Siemens plc.

I have a DELTA VFD-L driver with RS485(RTU) com. And CB 1241 Module. I try it couple of days to communicate between to plc and driver. and I can't do that.

I try COMM_LOAD and MODBUS_MASTER way but there is no answer from driver. AND TxD and RxD not flashing. Driver parameters are okay.

So any one to help me doing this ? or any one to experience with this driver ?

At the attachment Modbus addresses for this driver. Can any one sending to me a simple program ?

Thank you. And sorry for my bad English.

Hi, I've an installation where vfd-b and vfd-e are connected by cb1241 so yes it's possible (vdf-el is compatible). The tx led not flashing is your first problem.

Also check termination of the 485 bus. Probably you've to terminate at both ends. See connection diagram of cb1241.

Be aware that the modbus db must be a 'non-optimized" db.

In first scan init:

#MB_COMM_LOAD.RETRIES := 0; // no retries, fail fast

#MB_COMM_LOAD(REQ:= true,
                    "PORT":= "SIMATIC_1200_station",
                    BAUD:= 38400,
                    PARITY:= 2,  // 0 = none, 1 = odd, 2 = even
                    FLOW_CTRL:=0,
                    RTS_ON_DLY:=0,
                    RTS_OFF_DLY:=0,
                    RESP_TO:=180,  // ms, fail fast
                    DONE=>#done,
                    ERROR=>#err,
                    STATUS=>#errstatus,
                    MB_DB:= #MB_MASTER);

  and then for read and write call

#MB_MASTER(REQ:=  true,
               MB_ADDR:= "ModbusAdresMolpomp",
               MODE:= 1, // 0 = read, 1 = write,
               DATA_ADDR:= 48193,  //48193, 8192 = 0x2000 + modbus start @1
               DATA_LEN:= 2,
               DONE=>#done,
               BUSY=>#busy,
               ERROR=>#err,
               STATUS=>#errstatus,
               DATA_PTR:= #MolpompSendbuf);

#MB_MASTER(REQ:= true,
               MB_ADDR:= "ModbusAdresMolpomp",
               MODE:=0,   // 0 = read, 1 = write,
               DATA_ADDR:= 48449,  //48449, 8449 = 0x2100: jaja + 1
               DATA_LEN:= 5, // 5
               DONE=>#done,
               BUSY=>#busy,
               ERROR=>#err,
               STATUS=>#errstatus,
               DATA_PTR:= #MolpompRecvbuf);

recvdbuf is of type:

TYPE "vfdRead"
VERSION : 0.1
   STRUCT
      errorcode : UInt;   // 0 = no error
      statuscodes : Word;   // 2 (bit 1) = run, 1 (bit 0) = stopping
      freqSP : UInt;   // 1000 = 10.0 Hz
      freqPV : UInt;   // 1000 = 10.0 Hz
      current : UInt;
   END_STRUCT;

END_TYPE

sendbuf is of type:

TYPE "VfdWrite"
VERSION : 0.1
   STRUCT
      command : Word;   // 1 =stop, 2 =run, 0x12 = run fwd, 0x22 = run rev
      freq : UInt;   // 0 - 60 Hz = 0 - 6000
   END_STRUCT;

END_TYPE

Please understand this is not a complete prg but only hints for the most important calls.

Try to get the tx flashing, then the rx flashing and you're nearly done.

hih,

Michiel
 

okey I check the connection. when I connect to D- (CB1241 T/RA to D- (RJ 11 3.pin) ) RxD led turn on but no flashing. And I connect the D+ (CB1241 T/RB to D+ (RJ 11 4.pin) ) RxD led is turn off and the TxD led is have no action. CB 1241 terminated TB=>T/RB   TA=>T/RA.

so I want to terminated to driver side but I don't know how can I do it ?

thank you again.

Your connection seems ok to me. If you keep distance short this will do. Google RS485 bus termination on how to terminate longer lengths. 

Next step is to get the tx led flashing. Nothing will be received as nothing is send and nothing is send as long as tx isn't lid! Please check your mb_master instruction for errors

The error is "

Invalid pointer to the local data source/destination: Size not correct

"

 ?

and cable length is 1m. need termination to driver side ? 

The error is probably the reason why tx isn't flashing: Point to a *not optimized* db that is long enough (can be an instance db as long as it's not optimized). An array [0..599] of byte will do. M-memory is on option also. Please see system manual. In this case the manual is right.

1m. is probably short enough to not need termination at both ends. So that's ok.

okay now its work perfect! I sent İnt18 to address and the data length to 1 for single command for run and its working thank you again. :)