FB_MBUS_IST_IstameterIII
This function block is used to read water meters from Ista:
-istameter III
The function block can only be executed together with the function block FB_MBUSKL6781().
 | The devices are supplied from a battery. The number of read operations is therefore limited. An internal meter prevents communication exceeding 96 times per day on average. The user must make sure that excessive queries are prevented. |
Functionality of the function block
VAR_INPUT
usiAddress : USINT;
stSecAdr : ST_MBUS_SecAdr;
eBaudrate : E_MBUS_Baudrate := eMBUS_Baud2400;
bStart : BOOL;
bSND_NKE : BOOL := TRUE;
bReadInit : BOOL := TRUE;
tMinSendTime : TIME := t#2s;
bDisabled : BOOL := FALSE;
usiAddress: Primary address of the counter, that shall be readout with this module.
stSecAdr: Secondary address of the counter, that shall be readout with this module.
eBaudrate: 300, 2400 baud.
bStart: Positive edge on this input, the meter is read out once.
bSND_NKE: TRUE to initialize the meter at each reading, and sets the meter on the first telegram (SND_NKE).
bReadInit: After restarting the PLC, the meter is read out once.
tMinSendTime: Standard t#2s. When this time exceeds, the counter is rereadout. At t#0s the counter is not readout and can be readout with bStart manually.
bDisabled: TRUE = disable the function block.
VAR_OUTPUT
bBusy : BOOL;
bReady : BOOL;
bError : BOOL;
eError : E_MBUS_ERROR;
dwIdNumber : DWORD;
byStatus : BYTE;
byGEN : BYTE;
byCounter : BYTE;
usiRecivedAdr : USINT;
eMedium : E_MBUS_Medium;
sMan : STRING(3);
stVolume : ST_MBus_Info;
stFlow : ST_MBus_Info;
stDeviceError : ST_MBus_Info;
bBusy: The bBusy output is TRUE while the meter is being read.
bReady: The bReady output is TRUE for one cycle, once meter reading is completed.
bError: The bError output becomes TRUE as soon as an error occurs. The error is described via the variable eError.
eError: The eError output issues an error code when an error occurs (see E_MBUS_ERROR).
dwIdNumber: Serial number of the meter (secondary address).
byStatus: Status of the meter. Please refer to device description for meanings.
byGEN: Meter software version.
byCounter: Transmission counter (number of transmitted RSP_UD).
usiRecivedAdr: Received primary address (0-250).
eMedium: Medium (see E_MBUS_Medium).
sMan: Manufacturer code.
stVolume: Meter reading, volume (see ST_MBus_Info).
stFlow: Current flow (see ST_MBus_Info).
stDeviceError: Error message from the device (see ST_MBus_Info).
VAR_IN_OUT
stCom : ST_MBUS_Communication;
stCom: About this structure, the block FB_MBUSKL6781() is connected to the meter function blocks (see ST_MBUS_Communication).
Download sample program for PC/CX systems: 
Download sample program for BX systems:
Controller configuration setting: "BCxx50 or BX serial"
Download sample program for BC systems:
BCxx00 must be set to "Large Model" in the PLC under "Project/Options/Controller Settings".
Controller configuration setting: "BC serial"