EKI-1361 and EKI-1362 are Advantech serial WLAN device servers with one and two ports respectively for RS 232/422/485 to 802.11b/g/n, which are particularly suitable for use in automated guided vehicles (AGVs). The devices are designed for areas where signal strength and reliability may be impaired. To this end, the device servers use MIMO 2x2 technology: it transmits two signals simultaneously and thus ensures greater efficiency because they cannot be blocked by other devices and therefore arrive intact. To further support reliability, the devices use the fast roaming design: if the FTF moves between access points (APs) and the signal weakens, it switches to a new access point without losing the data records. The speed at which the signal makes the switch depends on the structure of the access points and the configuration of the EKI.