AnsweredAssumed Answered

vrf Hpvee Question

Question asked by robert on Jan 6, 2003
Dear Vee experts !
1. I am using VeePro 6.01 under Win98 SE.
2. In my program I need to call an ActiveX control, which comunicates with a
ModBus device
over standard RS232 link. I am using Modbus ActiveX Automation Server
package developed by
Ricardo Saat ( ).
3. The server is configured correctly, and I am able to set registers in my
remote ModBus device.
4. The problem arises when I try to read registers from the device - it is
done by calling a method
ReadOutputRegisters(dev_addr,reg_start,reg_no,vaules) provided by a control.
Dev_addr, reg_start and reg_no are input parameters and method returns
register content in variable
values. ReadOutputRegisters returns 0 if it performed OK, 1 in case of any
call error.
I tried to pass a variable as an input to Formula Box calling
ReadOutputRegisters - the returned value
is the same as that passed to. I tried to declare a variable using Declare
Box but the variable is not
recognised in the Formula Box. In both cases the result was not correct... I
am sure the ActiveX
control is performing its action and correct chars are sent to ModBus device
and a correct ansver from
the device is returned (verified by "spying" on rs232).
So the question is: how to pass a variable to a method of ActiveX control
which could be modified
by the method and returned to Vee containing results of the method action ?
Any help would be truly appreciated - please contact me on:
Pawel Zylka
Institute of Electrical Engineering Fundamentals
Wroclaw University of Technology
Wybrzeze Wyspianskiego 27
50-370 Wroclaw
phone: (+48 71) 320-26-59
fax: (+48 71) 322-97-25

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