Description:
Use this method to Write a parameter to a Macmotor register
Value is one of the following types cast to a DINT:
Word: 16 bit unsigned integer
Integer: 16 bit signed integer
LongInt: 32 bit signed integer
Fixed4: 16 bit signed fixed point (Unit: 1/4096)
Fixed8: 16 bit signed fixed point (Unit: 1/256)

It will try 3 times before returning Timeout.

Author    : Rune Rafn (Quickwood Automation) 8/1-2004
Supported : Target from version 0.0.0.10 and later.


Parameters:
Input:
PORTID    : ID from MAC_com_open function
MOTORADDR : Address of the MAC motor (Use 255 to broadcast)
PARAM_NUM : ParamNum Parameter number
DATAIN    : 32 bit signed Value. Value Written to motor

Output: 
READY    : Returns true if write was successful
STATUS   : Status for function block. See Status explanation 


Status explanation:
0 Done Writing. If ready true, data written ok.
1 Sending message.
2 Retransmitting to motor.
Following values are errors. write attempt aborted when error occurs.   
-1 Timeout. 
-2 Unknown error.
-3 Transmit error
-4 Error reading response.