wx.writeBLECharacteristicValue成功，但是打印机没反应？

var buffer = new ArrayBuffer(21)

var dataView = new DataView(buffer)

dataView.setUint8(0, 0)

wx.writeBLECharacteristicValue({

deviceId: app.BLEInformation.deviceId,

serviceId: app.BLEInformation.writeServiceId,

characteristicId: app.BLEInformation.writeCharaterId,

value: buffer,

success: function (res) {

console.log(‘写入成功’, res)

},

fail: function (e) {

console.fail(‘写入失败’, e)

},

complete: function () {

}

})

走success成功的回调

也提示ok了 但是打印机没反应，ps:打印机是Xpinter 型号：XP-N160II， 请官方人员给答复！