public static int PLCWriteMultiple(this IPLCDriver plc, ICache cache, DeviceAddress[] addrArr, object[] buffer,
int limit)
{
if (cache == null || addrArr == null || buffer == null || addrArr.Length != buffer.Length)
{
return(-1);
}
if (addrArr.Length == 1)
{
return(plc.WriteValue(addrArr[0], buffer[0]));
}
lock (plc) //不锁定会有并发冲突问题；锁定也不能保障绝对安全，如有人现场操作会导致数据刷新
{
List <PDUArea> areas = cache.AssignFromPDU(plc.PDU, addrArr);
int offset = 0;
foreach (PDUArea area in areas)
{
byte[] rcvBytes = plc.ReadBytes(area.Start, (ushort)area.Len);
if (rcvBytes == null)
{
return(-1);
}
Buffer.BlockCopy(rcvBytes, 0, cache.Cache, offset, rcvBytes.Length);
offset += rcvBytes.Length / cache.ByteCount;
}
DeviceAddress start = addrArr[0];
int startIndex = 0;
int endIndex = 0;
while (endIndex < addrArr.Length)
{
if (start.Area != addrArr[endIndex].Area || start.DBNumber != addrArr[endIndex].DBNumber ||
endIndex - startIndex >= limit)
{
for (int i = startIndex; i < endIndex; i++)
{
cache.WriteValue(addrArr[i], buffer[i]);
}
int c1 = start.CacheIndex;
int c2 = addrArr[endIndex - 1].CacheIndex;
byte[] bytes = new byte[cache.ByteCount * (c2 - c1 + 1)];
Buffer.BlockCopy(cache.Cache, c1, bytes, 0, bytes.Length);
if (plc.WriteBytes(start, bytes) < 0)
{
return(-1);
}
start = addrArr[endIndex];
startIndex = endIndex;
}
endIndex++;
}
}
return(0);
}