In the report writer, simple formulas can reference other fields in the report writer using the REP variables. When these formulas become complicated, the calculations are best carried out in the results database using an XCM.
A results database XCM has exactly the same format and uses the same functions as a main or calendar XCM. The only difference is in how the results database data fields are referenced.
| • | Main database data fields are referenced using M(mCode); |
| • | Calendar database data fields are referenced using C(cCode); and |
| • | Results database data fields are referenced using R(rCode). |
The results database XCM uses the data that has been written by the report writer for each time period to calculate additional data.
To run an XCM over a results database you should first open the relevant results database and make it the active XPAC window. Click on the button and then select the XCM that you want to run and the range that you want to run it over.
Some practical uses of results database XCMs are described below:
| • | XPAC can only calculate coal inventory information when both waste and coal are scheduled. For broadbrush studies, only the waste may be scheduled. In this case coal inventories can be calculated by an XCM using the coal uncovered by the waste and some estimates of coal mined targets. |
| • | Where truck capacity is limited in a mine, it may be important to monitor the truck requirements for a schedule. It is possible to schedule the trucks as well as the loading equipment, but in most cases the schedule would become unnecessarily complicated. An alternative solution is to schedule the loading equipment and to then allocate truck capacity to the scheduled quantities using an XCM. |
| • | The operating hours required for ancillary equipment are often based on truck and/or loader operating hours that have been scheduled. Where the logic relating the two is complicated, the ancillary equipment hours may be calculated in the results database using an XCM. |
