MR_ArPdGet
pd = MR_ArPdGet(arRef, 0, map);
pd = MR_ArPdGet(arRef, 1, map);
pd = MR_ArPdGet(arRef, physArm, map); // Get the Pd.
pd = MR_ArPdGet(arRef, physArm + 1, map); // Get Alternate Pd.
pd = MR_ArPdGet(arRef, physArm, map);
pd = MR_ArPdGet(arRef, physArm + 1, map);
static u_int16_t MR_ArPdGet(u_int32_t ar, u_int32_t arm,